> For the complete documentation index, see [llms.txt](https://help.smartico.ai/welcome/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.smartico.ai/welcome/technical-guides/communication-gateways/supported-mail-gateways.md).
# Supported Mail gateways
Smartico delivers outbound email communications through native integrations with industry-leading Email Service Providers (ESPs) and custom gateway protocols. Operators can connect multiple mail gateways simultaneously to segregate transactional and marketing traffic, route campaigns across different brands, and optimize inbox placement.
Email gateways are configured in the Smartico Back-Office under **Label Settings → Gateways → Mail**. Each gateway connection manages authentication credentials, webhook callback URLs for delivery and engagement tracking, default sending pools, and sender address definitions.
***
## How Email Gateway Configuration Works
When setting up or editing an email gateway, the Back-Office provides a 4-step configuration wizard:
1. **Provider Selection**: Choose your email delivery provider from the supported catalog or select the custom gateway option.
2. **Conditions & Scope**:
* **Gateway Name**: A friendly label for internal identification.
* **Default Gateway**: Set whether this gateway is the primary default mail provider for the label.
* **Brand Targeting**: Restrict the gateway to specific brands or apply it across all brands.
* **Custom Conditions (Based on the user state Properties)**: If dynamic gateway selection properties are configured for the label, specify one or more profile attribute values (such as country, VIP tier, brand, or language) to restrict the gateway to matching players during automatic gateway routing. You can request that Smartico Success Manager enable them based on your needs.
3. **Authentication & Configuration**: Enter API keys, hostnames, endpoint URLs, and advanced provider-specific settings. A unique **Callback URL** is generated and displayed on this screen for providers that support webhook status synchronization. Copy this full URL to configure delivery and engagement tracking in your email service provider's webhook settings.
* **Additional Parameters**: A flexible key-value parameter editor is available to pass optional or advanced provider arguments not exposed in the standard form fields.
4. **Options for From & Reply Addresses**: Configure sender and reply-to email addresses separated into two independent pools:
* **Marketing Emails**: Promotional newsletters, retention offers, and automated marketing flows.
* **Operational Emails**: Password resets, account verifications, KYC requests, and transactional alerts.
***
### Sender Address Updates & Immutability Rules
When updating existing From or Reply-To addresses on an active gateway:
* **Existing Addresses Cannot Be Removed**: Once created, sender options cannot be deleted directly from the gateway if they are already referenced by active campaigns.
* **Automatic Campaign Updates**: When modifying or adding new From or Reply-To options, Smartico automatically updates existing campaign configurations if the new list covers previous mappings.
* **Confirmation Screen**: If changes to sender addresses require manual reassignment across existing templates, a review screen prompts the operator to confirm and map the replacement options before saving.
***
### Deleting a Mail Gateway & Campaign Migration
When deleting a configured email gateway, the Back-Office prevents orphan campaign configurations by requiring a migration strategy:
* **Migrate to Auto-Selection**: Automatically switches all campaigns currently linked to the deleted gateway to use automatic provider selection based on brand and user routing conditions.
* **Migrate to Another Provider**: Reassigns linked campaigns to a specified replacement gateway, requiring the operator to map replacement From and Reply-To addresses.
***
## Supported Email Gateways Catalog
Below is the complete reference of email service providers natively supported by Smartico, detailing their required credentials, supported additional parameters, and external provider-side setup requirements.
***
### 1. Amazon SES
Native integration with Amazon Simple Email Service (SES), the Amazon Web Services cloud email platform.
* **Provider links**: [Website](https://aws.amazon.com/ses/) · [Manage access keys for IAM users (Access Key ID / Secret)](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_access-keys.html) · [Create and verify identities (sender domain / address)](https://docs.aws.amazon.com/ses/latest/dg/creating-identities.html) · [SES notifications through Amazon SNS (bounces, deliveries)](https://docs.aws.amazon.com/ses/latest/dg/monitor-sending-activity-using-notifications-sns.html) · [SES endpoints and regions](https://docs.aws.amazon.com/general/latest/gr/ses.html)
* **Back-Office Configuration Fields**:
* `AWS Access Key ID` *(Required)*: IAM user access key with SES sending permissions (`ses:SendEmail`, `ses:SendRawEmail`).
* `AWS Secret Access Key` *(Required)*: Associated IAM secret access key.
* `AWS Region` *(Required)*: The AWS region hosting your SES service (e.g., `us-east-1`, `eu-west-1`, `sa-east-1`).
* `List-Unsubscribe` *(Optional)*: Unsubscribe URL or mailto link for RFC 8058 email headers.
* `List-Unsubscribe-Post` *(Optional)*: Typically set to `List-Unsubscribe=One-Click` to enable native unsubscribe buttons in Gmail and Yahoo.
* **Provider-Side Setup**:
* Verify your sending domain and individual sender email addresses under **Amazon SES → Verified Identities**.
* Configure DNS records (DKIM CNAME records, SPF TXT record, DMARC policy).
* Move your AWS SES account out of the SES sandbox to enable production sending to unverified recipients.
* Set up an Amazon SNS Topic subscribed to your SES Configuration Set to forward bounce, complaint, and delivery event notifications to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 2. SendGrid
Enterprise cloud email delivery by Twilio SendGrid.
* **Provider links**: [Website](https://sendgrid.com) · [API keys](https://www.twilio.com/docs/sendgrid/ui/account-and-settings/api-keys) · [Event Webhook (delivery events)](https://www.twilio.com/docs/sendgrid/for-developers/tracking-events/getting-started-event-webhook) · [IP pools](https://www.twilio.com/docs/sendgrid/ui/account-and-settings/ip-pools)
* **Back-Office Configuration Fields**:
* `SendGrid API Key` *(Required)*: API key with **Mail Send** permissions.
* `IP Pool Name` *(Optional)*: The identifier of the dedicated IP pool configured in your SendGrid account.
* `Generate Plain Text` *(Optional, Default: False)*: When enabled, Smartico automatically extracts a plain-text fallback version from the HTML template.
* `List-Unsubscribe` / `List-Unsubscribe-Post` *(Optional)*: RFC 8058 one-click unsubscribe header definitions.
* **Additional Supported Parameters**:
* `region`: Supports `"eu"` or `"global"`. When set to `"eu"`, API traffic is directed to SendGrid's European data residency endpoint.
* **Provider-Side Setup**:
* Complete **Sender Authentication** (Domain Authentication via CNAME records for SPF and DKIM).
* Navigate to **Settings → Mail Settings → Event Webhook** in the SendGrid console.
* Enable Event Webhook, paste the Smartico Callback URL copied from the gateway configuration screen in the Back-Office, and check all event notifications: *Processed, Dropped, Delivered, Deferred, Bounce, Open, Click, Spam Report, Unsubscribe*.
***
### 3. Mailgun
Developer-focused transactional and marketing email platform.
* **Provider links**: [Website](https://www.mailgun.com) · [Getting started sending email](https://documentation.mailgun.com/docs/mailgun/get-started) · [API authentication (API key)](https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth) · [Webhooks (delivery events)](https://documentation.mailgun.com/docs/mailgun/user-manual/webhooks/webhooks) · [Messages API (send)](https://documentation.mailgun.com/docs/mailgun/api-reference/send/mailgun/messages)
* **Back-Office Configuration Fields**:
* `Mailgun API Endpoint URL` *(Required)*: The sending API URL for your domain (e.g., `https://api.mailgun.net/v3/yourdomain.com/messages` or EU endpoint `https://api.eu.mailgun.net/v3/yourdomain.com/messages`).
* `Mailgun API Key` *(Required)*: Primary Sending API key or domain-level sending key.
* `Optional Sending IP Address` *(Optional)*: Dedicated IP address to bind to outgoing messages.
* `Generate text/plain version on MailGun side` *(Optional, Default: False)*: Lets Mailgun generate text versions automatically.
* `Add email extra parameters to o:tag` *(Optional, Default: False)*: Passes campaign metadata into Mailgun's tagging parameters for campaign aggregation.
* `Add email extra parameters amp-html` *(Optional, Default: False)*: Enables AMP for Email processing when AMP HTML templates are used.
* **Additional Supported Parameters**:
* `List-Unsubscribe` / `List-Unsubscribe-Post`: Header mapping for one-click unsubscribe.
* `X-Report-Abuse-To`: Abuse reporting header.
* `o:tracking` *(Optional, Default: `true`)*: Toggles Mailgun message tracking.
* `o:tracking-clicks` *(Optional, Default: `false`)*: Toggles Mailgun click tracking in message content.
* `o:tracking-opens` *(Optional, Default: `true`)*: Toggles Mailgun open tracking in message content.
* **Provider-Side Setup**:
* Add and verify your sending domain with required DNS records (SPF TXT record, DKIM TXT record, CNAME tracking record).
* Go to **Sending → Webhooks** in Mailgun, select your domain, and add webhooks pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office for *Delivered Messages, Permanent Failure, Temporary Failure, Clicks, Opens, Spam Complaints, Unsubscribes*.
***
### 4. Brevo (SendinBlue)
European marketing and transactional email platform.
* **Provider links**: [Website](https://www.brevo.com) · [Brevo API: getting started (create the API key)](https://developers.brevo.com/docs/getting-started) · [Send a transactional email](https://developers.brevo.com/docs/send-a-transactional-email) · [Transactional webhooks (delivery events)](https://developers.brevo.com/docs/transactional-webhooks)
* **Back-Office Configuration Fields**:
* `API Key` *(Required)*: v3 API Key generated from Brevo Settings.
* **Provider-Side Setup**:
* Verify your sending domain and sender email addresses under **Senders & IP → Domains** in Brevo.
* Configure DKIM and Brevo code DNS records.
* Navigate to **Transactional → Settings → Webhook** and create a webhook pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office, subscribing to: *Sent, Delivered, Soft Bounce, Hard Bounce, Spam, Opened, Clicked, Unsubscribed*.
***
### 5. SparkPost
High-volume cloud email delivery infrastructure. SparkPost is part of Bird (formerly MessageBird).
* **Provider links**: [Website](https://www.sparkpost.com) · [API overview](https://developers.sparkpost.com/api/) · [API key management](https://bird.com/docs/knowledge-base/account-security/api-keys) · [Event webhooks API](https://developers.sparkpost.com/api/webhooks/) · [Sending domains API](https://developers.sparkpost.com/api/sending-domains/)
* **Back-Office Configuration Fields**:
* `URL` *(Required)*: SparkPost API base endpoint (e.g., `https://api.sparkpost.com` for US or `https://api.eu.sparkpost.com` for EU).
* `Authentication Token` *(Required)*: REST API Key with `Transmissions: Read/Write` and `Webhooks: Read/Write` permissions.
* `Custom Headers` *(Required, Map format)*: Custom key-value header pairs to include with every transmission.
* **Provider-Side Setup**:
* Verify Sending Domain and configure CNAME / TXT DNS records for DKIM and bounce handling.
* Configure a Webhook in SparkPost targeting the Smartico Callback URL copied from the gateway configuration screen in the Back-Office for message delivery, bounce, spam complaint, and click/open events.
***
### 6. UniOne
High-performance email gateway with optimized deliverability routing.
* **Provider links**: [Website](https://unione.io) · [UniOne documentation](https://docs.unione.io/en/) · [Web API reference (API key, email/send, webhook/set)](https://docs.unione.io/en/web-api-ref)
* **Back-Office Configuration Fields**:
* `API Key` *(Required)*: UniOne project API key.
* `API Endpoint` *(Required, Default: `https://eu1.unione.io/en/transactional/api/v1/email/send.json`)*: Regional sending endpoint.
* **Additional Supported Parameters**:
* `Custom Backend Identifier`: Optional backend routing identifier used for dedicated infrastructure segregation.
* `Bypass Unsubscribe Suppression`: Optional setting to bypass provider-side global suppression lists for critical operational messages.
* **Provider-Side Setup**:
* Authenticate domain via DKIM and SPF records in the UniOne control panel.
* Configure an event notifications webhook pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
### 7. Mailjet
Transactional and marketing email provider.
* **Provider links**: [Website](https://www.mailjet.com) · [Getting started: prerequisites (API key and secret)](https://dev.mailjet.com/docs/email-api/getting-started/prerequisites) · [Send API v3.1](https://dev.mailjet.com/docs/email-api/send-api-v31/send-basic-email) · [Event webhooks](https://dev.mailjet.com/docs/email-api/webhooks/webhooks-overview)
* **Back-Office Configuration Fields**:
* `Mailjet API Endpoint URL` *(Required)*: Base API URL (e.g., `https://api.mailjet.com/v3.1/send`).
* `Mailjet Account Username` *(Required)*: Mailjet API Public Key.
* `Mailjet Account Password` *(Required)*: Mailjet API Secret Key.
* **Provider-Side Setup**:
* Validate sending domain and sender addresses under **Account Settings → Sender domains & addresses**.
* In **Account Settings → Event Tracking (Webhooks)**, configure the Smartico Callback URL copied from the gateway configuration screen in the Back-Office for events: *Sent, Opened, Clicked, Bounced, Blocked, Spam*.
***
### 8. Infobip
Omnichannel communication platform email gateway.
* **Provider links**: [Website](https://www.infobip.com) · [Email over API](https://www.infobip.com/docs/email/email-over-api) · [API authentication (API key)](https://www.infobip.com/docs/essentials/api-essentials/api-authentication) · [Base URL (personal host)](https://www.infobip.com/docs/essentials/api-essentials/base-url) · [Email API reference (delivery reports)](https://www.infobip.com/docs/api/channels/email)
* **Back-Office Configuration Fields**:
* `Infobip Email Host` *(Required)*: Dedicated API subdomain/host (e.g., `xxxxx.api.infobip.com`).
* `Infobip API Key` *(Required)*: API key (e.g., `App Z9f8e7d6c...`).
* `Email Callback URL` *(Optional)*: Webhook URL for status reports.
* `Email Tracking URL` *(Optional)*: Tracking URL for open/click notifications.
* **Provider-Side Setup**:
* Verify sending domain in the Infobip portal and add SPF/DKIM DNS records.
* Configure Delivery Reports to post status payloads to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 9. Mailchimp Transactional (Mandrill)
Mailchimp's dedicated transactional email delivery service.
* **Provider links**: [Website](https://mailchimp.com/features/transactional-email/) · [Transactional API quick start (API key)](https://mailchimp.com/developer/transactional/guides/quick-start/) · [Track and respond to email activity with webhooks](https://mailchimp.com/developer/transactional/guides/track-respond-activity-webhooks/)
* **Back-Office Configuration Fields**:
* `Mandrill API Key` *(Required)*: API key generated in Mandrill settings.
* **Provider-Side Setup**:
* Complete Domain Verification and Authentication (SPF and DKIM records) in Mandrill.
* Under **Settings → Webhooks**, add a webhook with the Smartico Callback URL copied from the gateway configuration screen in the Back-Office, subscribing to: *Message Is Sent, Message Is Bounced, Message Soft-Bounces, Message Is Opened, Message Is Clicked, Recipient Unsubscribes, Message Is Marked As Spam*.
***
### 10. GetResponse
Automated email marketing platform.
* **Provider links**: [Website](https://www.getresponse.com) · [Where to find the API key](https://www.getresponse.com/help/where-do-i-find-the-api-key.html) · [API v3 case study: auth header and from-fields (fromFieldId)](https://apidocs.getresponse.com/v3/case-study) · [API reference](https://apireference.getresponse.com/)
* **Back-Office Configuration Fields**:
* `GetResponse API Endpoint URL` *(Required)*: API endpoint (e.g., `https://api.getresponse.com/v3` or GetResponse MAX 360 enterprise domain `https://api3.getresponse360.pl/v3`).
* `GetResponse API Key` *(Required)*: API Key from GetResponse Account Settings.
* `From Email Address Field ID` *(Required)*: The internal GetResponse identifier corresponding to the verified sender email.
* `Reply-To Email Address Field ID` *(Required)*: The internal GetResponse identifier corresponding to the reply-to address.
* **Provider-Side Setup**:
* Verify sending domain and create sender email identities in GetResponse.
* Retrieve the corresponding `fromFieldId` and `replyToFieldId` via the GetResponse API or management console.
* Set up Webhook subscriptions for delivery and engagement callbacks to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 11. SendPost
High-performance developer email delivery platform.
* **Provider links**: [Website](https://sendpost.io) · [SendPost docs introduction](https://docs.sendpost.io/) · [API reference introduction (API key header)](https://docs.sendpost.io/api-reference/introduction) · [Sub-accounts (each has its own API key)](https://docs.sendpost.io/api-reference/sub-account/create-a-new-sub-account)
* **Back-Office Configuration Fields**:
* `Host` *(Required)*: API sending URL (e.g., `https://api.sendpost.io/api/v1/subaccount/email`).
* `API Key` *(Required)*: Sub-account API Key (`X-SubAccount-ApiKey`).
* `Groups` *(Required)*: Comma-separated list of group names for message categorization and tagging.
* `IP Pool` *(Required)*: Dedicated IP pool name (or default pool identifier).
* `Campaign Header` *(Optional)*: Custom campaign identifier passed in headers.
* `Track clicks?` *(Optional, Default: True)*: Toggle native click tracking.
* `Track opens?` *(Optional, Default: True)*: Toggle native open tracking.
* **Provider-Side Setup**:
* Verify domain DNS settings (SPF, DKIM, DMARC, Return-Path).
* Configure Webhook endpoints in the SendPost dashboard pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 12. General SMTP Provider
Standard SMTP protocol integration supporting any RFC-compliant mail server (Postfix, Exim, Microsoft 365, Google Workspace, on-premise relays).
* **Back-Office Configuration Fields**:
* `Username` *(Required)*: SMTP authentication username.
* `Password` *(Required)*: SMTP authentication password.
* `SMTP Host` *(Required)*: Hostname or IP of the mail server (e.g., `smtp.office365.com`, `smtp.gmail.com`).
* `SMTP Port` *(Required)*: SMTP port (e.g., `587` for STARTTLS, `465` for SSL, `25` for unencrypted relays).
* `SMTP Authentication` *(Required, Default: `true`)*: Enable SMTP AUTH.
* `Enable STARTTLS` *(Required, Default: `true`)*: Enforce TLS encryption during handshake.
* `SMTP Timeout` *(Optional, Default: `60000` ms)*: Socket read timeout.
* `Connection Timeout` *(Optional, Default: `60000` ms)*: Socket connection timeout.
* `mail.smtp.writetimeout` *(Optional, Default: `60000` ms)*: Socket write timeout in milliseconds.
* **Provider-Side Setup**:
* Whitelist Smartico egress sending IPs on your firewall or mail transfer agent (MTA).
* Ensure the authenticated user has authorization to send on behalf of the configured From addresses.
* Configure SPF records on your DNS to authorize the SMTP server hostname/IP.
***
### 13. Elastic Email
Cost-effective email delivery infrastructure.
* **Provider links**: [Website](https://elasticemail.com) · [How to send emails via API (create the API key)](https://help.elasticemail.com/en/articles/2376694-how-to-send-emails-via-api) · [Notification settings (webhook URL)](https://help.elasticemail.com/en/articles/4804685-notification-settings) · [REST API v4 documentation](https://elasticemail.com/developers/api-documentation/rest-api)
* **Back-Office Configuration Fields**:
* `URL` *(Required)*: Elastic Email REST endpoint (e.g., `https://api.elasticemail.com/v4/emails/transactional`).
* `Api Key` *(Required)*: Elastic Email API key.
* **Provider-Side Setup**:
* Verify sending domain with SPF, DKIM, and tracking CNAME records.
* Create a notifications webhook in the Elastic Email console pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 14. Dotdigital
Enterprise omnichannel marketing automation platform.
* **Provider links**: [Website](https://dotdigital.com) · [Set up an API user (username / password)](https://marketing.developer.dotdigital.com/docs/setting-up-an-api-user) · [Get started with the API (region endpoint URL)](https://marketing.developer.dotdigital.com/docs/getting-started-with-the-api) · [Transactional email](https://marketing.developer.dotdigital.com/docs/transactional-email)
* **Back-Office Configuration Fields**:
* `URL` *(Required)*: Dotdigital transactional email endpoint (e.g., `https://r1-api.dotdigital.com/v2/email`).
* `Authentication Username` *(Required)*: API user username.
* `Authentication Password` *(Required)*: API user password.
* **Provider-Side Setup**:
* Add and verify custom from addresses in the Dotdigital account.
* Configure the Webhook callback URL using the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 15. Karix
Enterprise communication gateway.
* **Provider links**: [Website](https://www.karix.com) · [Karix Email product page](https://www.karix.com/products/email/)
* **Back-Office Configuration Fields**:
* `Karix API Endpoint URL` *(Required)*: Sending URL provided by Karix (e.g., `https://ejson.instaalerts.zone/sendEmail`).
* `Karix Account Username` *(Required)*: Karix username for Basic Authentication.
* `Karix Account Password` *(Required)*: Karix password.
* **Provider-Side Setup**:
* Authorize Smartico egress IPs on Karix's IP access control list.
* Register approved From and Reply-To email addresses in the Karix console.
* Configure delivery feedback pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 16. Moosend
Marketing automation and transactional email platform.
* **Provider links**: [Website](https://moosend.com) · [Moosend API documentation (API key, endpoints)](https://docs.moosend.com/api-documentation?lang=en_US) · [Create a transactional campaign](https://docs.moosend.com/user-guide/articles/KnowledgeBase/54384-create-a-transactional-campaign?lang=en_US) · [API: manage a transactional campaign](https://docs.moosend.com/api-documentation/articles/KnowledgeBase/54597-Manage-a-transactional-campaign?lang=en_US)
* **Back-Office Configuration Fields**:
* `API Key` *(Required)*: MooSend API Key (**Settings → API key**).
* `API Endpoint URL` *(Optional, Default: `https://api.moosend.com/v3/campaigns/transactional/send.json`)*: Custom proxy or regional endpoint.
* `Transactional Campaign Name` *(Optional)*: Name of the MooSend transactional campaign under which message delivery analytics will be grouped.
* **Provider-Side Setup**:
* Complete Sender Domain verification with SPF and DKIM DNS records.
* Ensure sender email addresses are registered and confirmed in MooSend.
***
### 17. Telesign
Enterprise communication and security delivery network. Smartico sends through the Masiv email API (Masiv and Telesign are both part of Proximus).
* **Provider links**: [Website](https://www.telesign.com) · [Messaging: set up email for your account](https://developer.telesign.com/enterprise/docs/messaging-set-up-email-for-your-account) · [Messaging: send message via email (callbacks)](https://developer.telesign.com/enterprise/docs/messaging-send-message-via-email) · [Masiv email API documentation (endpoint used by the Smartico sender)](https://masivapp.notion.site/API-Documentation-7f55c68f83634b0aadc18bfaad7975a2)
* **Back-Office Configuration Fields**:
* `URL` *(Required, Default: `https://api.masiv.masivian.com/email/v1/delivery`)*: Masiv/Telesign delivery endpoint.
* `Basic Auth User` *(Required)*: API username.
* `Basic Auth Password` *(Required)*: API password.
* `Sender email` *(Required)*: Registered sender email address.
* `Template type` *(Required, Default: `TEXT`)*: Message content format descriptor.
* **Provider-Side Setup**:
* Register sender addresses with your Telesign account manager.
* Contact Telesign support to configure webhook delivery status routing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 18. Selzy
Regional email delivery platforms.
* **Provider links**: [Website](https://selzy.com) · [Where to get the Selzy API key](https://selzy.com/en/support/api/common/api-key/) · [sendEmail method](https://selzy.com/en/support/api/messages/sendemail/) · [API integration overview](https://selzy.com/en/support/category/api/)
* **Back-Office Configuration Fields**:
* `API Endpoint URL` *(Required)*: API send endpoint (e.g., `https://api.selzy.com/en/api/sendEmail` or `https://api.unisender.com/en/api/sendEmail`).
* `Account api_key` *(Required)*: API secret key.
* `From email` *(Required)*: Verified sender email address registered in the provider cabinet.
* `List id for Preview` *(Optional, Default: `1`)*: Unsubscribe list ID used for test sends and preview validations.
* **Provider-Side Setup**:
* Authenticate domain via DKIM and SPF in the account dashboard.
* Set up Webhook callbacks in Selzy or Unisender using the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 19. Unisender
Regional email delivery platform.
* **Provider links**: [Website](https://www.unisender.com) · [Where to get the Unisender API key (RU)](https://www.unisender.com/ru/support/api/common/api-key/) · [sendEmail method (RU)](https://www.unisender.com/ru/support/api/messages/sendemail/)
* **Back-Office Configuration Fields**:
* `Unisender API Endpoint URL` *(Required)*: API send endpoint (e.g., `https://api.unisender.com/en/api/sendEmail`).
* `Unisender Account api_key` *(Required)*: API secret key.
* `Unisender From email` *(Required)*: Verified sender email address registered in the Unisender cabinet.
* `List id for Preview` *(Optional, Default: `1`)*: Unsubscribe list ID used for test sends and preview validations.
* **Provider-Side Setup**:
* Authenticate domain via DKIM and SPF in the Unisender account dashboard.
* Set up Webhook callbacks using the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 20. SMTP.com
Dedicated transactional relay and API service.
* **Provider links**: [Website](https://www.smtp.com) · [API documentation (v4)](https://www.smtp.com/resources/api-documentation/) · [SMTP.com help center](https://knowledge.smtp.com/s/)
* **Back-Office Configuration Fields**:
* `SMTP API Endpoint URL` *(Required)*: API send URL (e.g., `https://api.smtp.com/v4/messages`).
* `SMTP Account api key` *(Required)*: API Key for Bearer token authorization.
* `SMTP channel` *(Required)*: Configured sending channel identifier in SMTP.com.
* **Provider-Side Setup**:
* Verify sending domain and configure sender reputations.
* Add a webhook callback pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 21. Zenvia
Omnichannel communications platform.
* **Provider links**: [Website](https://zenvia.com) · [Zenvia APIs reference v2 (email channel, subscriptions/webhooks)](https://zenvia.github.io/zenvia-openapi-spec/v2/) · [Zenvia for developers](https://zenvia.com/en/devs/) · [Tokens and webhooks for APIs (Zenvia Customer Cloud)](https://support.zenvia.com/kb/en/article/453693/tokens-webhooks-for-use-in-apis-zcc)
* **Back-Office Configuration Fields**:
* `API Endpoint URL` *(Required)*: Zenvia messages endpoint (e.g., `https://api.zenvia.com/v2/channels/email/messages`).
* `API Key` *(Required)*: Zenvia API token (`X-API-TOKEN`).
* **Provider-Side Setup**:
* Configure email channel and domain verification in the Zenvia portal.
* Subscribe to message status webhooks pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 22. Promotexter
Direct-to-carrier and email messaging gateway.
* **Provider links**: [Website](https://www.promotexter.com) · [Promotexter API reference](https://promotexter-api.redocly.app/api) · [Developer portal](https://promotexter.com/developer/) · [APIx: SMS and Email API](https://promotexter.com/apix-sms-and-email-api/)
* **Back-Office Configuration Fields**:
* `Promotexter API Endpoint URL` *(Required)*: Sending endpoint URL.
* `API Key` *(Required)*: Promotexter API key.
* `API Secret Key` *(Required)*: Promotexter API secret key.
* `Provider Unsubscription Test` *(Required)*: Text label for the provider-injected unsubscription footer link.
* `Optional Callback URL` *(Optional)*: Delivery receipt callback endpoint.
* **Provider-Side Setup**:
* Register domain and sender identities in Promotexter.
***
### 23. E-goi
Marketing and communication platform.
* **Provider links**: [Website](https://www.e-goi.com) · [Using E-goi's API (where to find the API key)](https://helpdesk.e-goi.com/511369-Using-E-gois-API) · [Sending transactional messages with E-goi](https://helpdesk.e-goi.com/708772-Sending-transactional-messages-with-E-goi) · [E-goi API v3 reference](https://developers.e-goi.com/api/v3/)
* **Back-Office Configuration Fields**:
* `Host` *(Required)*: E-goi API base URL (e.g., `https://api.egoiapp.com/v2`).
* `API Key` *(Required)*: E-goi API Key (`Apikey`).
* `List id` *(Required, Default: `1`)*: Contact list ID inside E-goi (falls back to `1` if omitted).
* `Sender id` *(Required, Default: `6`)*: Numeric sender ID registered in E-goi (falls back to `6` if omitted).
* `Reply to (id)` *(Required, Default: `3`)*: Numeric reply-to identifier registered in E-goi (falls back to `3` if omitted).
* **Provider-Side Setup**:
* Set up sender emails and contact lists in the E-goi cabinet.
* Configure webhook updates targeting the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 24. SessizMail
Turkish transactional email platform.
* **Back-Office Configuration Fields**:
* `Email Send URL` *(Required, Default: `https://api.sessizmail.com/api/v1/send/message`)*: API send endpoint.
* `API Key` *(Required)*: Server API key (`X-Server-API-Key`).
* `Send as Plain Text` *(Optional, Default: False)*: When enabled, converts HTML to plain text before dispatch.
* **Provider-Side Setup**:
* Register and verify sending domains in SessizMail.
* Configure status webhooks pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 25. MailerWeb
Transactional email delivery service.
* **Provider links**: [Website](https://www.mailerweb.com.br) · [Transactional API docs (email, WhatsApp, RCS)](https://api.mailerweb.com/transactional/docs)
* **Back-Office Configuration Fields**:
* `URL` *(Required, Default: `https://api.mailerweb.com/transactional/email/send`)*: API sending endpoint.
* `Basic Auth User` *(Required)*: Username for Basic Auth.
* `Basic Auth Password` *(Required)*: Password for Basic Auth.
* `Sender email` *(Required)*: Authorized sender email address.
* **Provider-Side Setup**:
* Register and verify sender email in the Mailerweb console.
***
### 26. SendWork
Specialized transactional email gateway.
* **Provider links**: [Website](https://www.sendwork.com.br)
* **Back-Office Configuration Fields**:
* `Email Send URL` *(Required)*: API endpoint.
* `SendWork Api Key` *(Required)*: API authorization key.
* **Provider-Side Setup**:
* Register customer credentials and verify domain settings with SendWork.
***
### 27. Wooxy
Multi-channel transactional email provider.
* **Provider links**: [Website](https://wooxy.com) · [API documentation](https://wooxy.com/api-documentation) · [Knowledge base](https://wooxy.com/knowledge-base)
* **Back-Office Configuration Fields**:
* `URL` *(Required)*: Wooxy API send URL (e.g., `https://api.wooxy.com/v3/mailer/send`).
* `Api Key` *(Required)*: Access token (`Access-Token`).
* **Provider-Side Setup**:
* Authenticate sending domain in Wooxy.
* Configure status callbacks pointing to the Smartico Callback URL copied from the gateway configuration screen in the Back-Office.
***
### 28. KREA
Custom enterprise messaging gateway.
* **Provider links**: [Website](https://krea.digital) · [OUTBOX.rest API documentation (KREA sending API)](https://outbox.gitbook.io/outbox-documentations/)
* **Back-Office Configuration Fields**:
* `Krea API Endpoint URL` *(Required)*: REST endpoint (e.g., `https://outbox.rest/send/message`).
* `Krea Authentication Key` *(Required)*: Authentication token (`AuthKey`).
* `Krea Message ID` *(Required)*: Pre-registered message/template ID in Krea.
* **Provider-Side Setup**:
* Create message templates and obtain the assigned message identifier from the Krea portal.
***
### 29. Broadcaster
Template-based email messaging gateway.
* **Back-Office Configuration Fields**:
* `URL` *(Required)*: Broadcaster API send endpoint.
* `Authorization Header` *(Required)*: Authorization header string (e.g., `Bearer `).
* `API Key` *(Required)*: Numeric API key.
* `Email Template ID` *(Required)*: Pre-configured email layout template ID.
* **Provider-Side Setup**:
* Define templates in the Broadcaster console and obtain the template numeric identifier.
***
### 30. Resend
Transactional email API for developers.
* **Provider links**: [Website](https://resend.com) · [Manage API keys](https://resend.com/docs/dashboard/api-keys/introduction) · [Verified domains](https://resend.com/docs/dashboard/domains/introduction) · [Webhooks](https://resend.com/docs/webhooks/introduction)
* **Back-Office Configuration Fields**:
* `API Key` *(Required)*: Your Resend API key.
* `Send Endpoint URL` *(Optional)*: Resend send email endpoint. Leave empty to use `https://api.resend.com/emails`.
* **Provider-Side Setup**:
* Verify your sending domain in Resend (SPF and DKIM records).
* Set the **Callback URL** from the gateway configuration screen in the Back-Office as the webhook URL in Resend, so delivery events reach Smartico.
***
### Your Secured Email (Generic Email Gateway)
Smartico's zero-PII secured email gateway protocol. Allows operators to send emails through proprietary backends without exposing player email addresses to Smartico.
* **Back-Office Configuration Fields**:
* `API Endpoint URL` *(Required)*: Client-hosted REST endpoint that receives the email dispatch request.
* `API Secret` *(Required)*: Secret key passed in the `Authorization` header.
* `Callback URL` *(Required)*: The Smartico endpoint where your server reports back message delivery and failure states.
* `Custom Headers` *(Optional, Map format)*: Custom HTTP headers included in every outbound request.
* `Custom Body Parameters` *(Optional, Map format)*: Additional static JSON fields injected into the request body.
* **Protocol Details**:
* For full specifications of the payload contract, authentication headers, and callback payloads, see [Secured Messaging Gateways (Email/SMS/IM)](/welcome/technical-guides/communication-gateways/secured-messaging-gateways-email-sms-im.md).
***
### Postmark & Netcore Email API (Pepipost)
Standard transactional email delivery providers.
* **Provider links**: Postmark: [Website](https://postmarkapp.com) · [Account and Server API tokens](https://postmarkapp.com/support/article/1008-what-are-the-account-and-server-api-tokens) · [Sending email with the API](https://postmarkapp.com/developer/user-guide/send-email-with-api) · [Webhooks overview](https://postmarkapp.com/developer/webhooks/webhooks-overview) · Netcore Email API (Pepipost): [Website](https://netcore.ai) · [Netcore Email API: getting started](https://emaildocs.netcore.ai/docs/netcore-email-api) · [API key management](https://emaildocs.netcore.ai/reference/api-key-management)
* **Back-Office Configuration Fields**:
* **Postmark** and **Netcore Email API (Pepipost)** are supported in the email provider selection catalog. Custom authentication tokens, endpoint addresses, and account headers can be passed using the Additional Parameters key-value editor on the gateway configuration screen.
* **Provider-Side Setup**:
* Verify sending domains and sender signatures in the respective provider management consoles.
* Configure DKIM, SPF, and MX records according to provider specifications to maintain inbox deliverability.
***
## Global Provider-Side DNS & Authentication Setup
For all third-party email service providers, proper DNS authentication is mandatory to prevent emails from landing in spam folders or being rejected by mailbox providers (Gmail, Yahoo, Microsoft Outlook, Apple Mail).
| Record Type | Host / Name | Purpose | Example Value |
| ---------------------------------- | ------------------------------------ | ---------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
| **SPF** (TXT) | `yourdomain.com` | Authorizes the ESP's servers to send emails on behalf of your domain. | `v=spf1 include:sendgrid.net include:mailgun.org ~all` |
| **DKIM** (TXT / CNAME) | `selector._domainkey.yourdomain.com` | Cryptographically signs outgoing messages to verify integrity. | `k=rsa; p=MIGfMA0GCSqGSIb3DQE...` |
| **DMARC** (TXT) | `_dmarc.yourdomain.com` | Defines policy for messages failing SPF/DKIM authentication. | `v=DMARC1; p=quarantine; rua=mailto:dmarc-reports@yourdomain.com` |
| **Custom Return-Path** (CNAME) | `pm-bounces.yourdomain.com` | Handles bounce processing and aligns envelope sender with From header. | Points to ESP bounce domain (e.g., `pm.app.sparkpost.com`) |
| **Custom Tracking Domain** (CNAME) | `links.yourdomain.com` | Whitelabels open and click tracking URLs to match your brand domain. | Points to ESP tracking server or Smartico [Branded Links](/welcome/technical-guides/communication-gateways/branded-links.md) |
***
## Unsubscribe Headers & Compliance (RFC 8058)
Major mailbox providers (including Gmail and Yahoo) enforce strict requirements for bulk marketing senders:
1. **One-Click Unsubscribe**: Senders must include `List-Unsubscribe` and `List-Unsubscribe-Post` headers so email clients can display a native "Unsubscribe" button at the top of the message.
2. **Supported Gateways**: Senders supporting self-service header injection in Smartico include Amazon SES, Twilio SendGrid, and Mailgun.
3. **Configuration**:
* `List-Unsubscribe`: Set to your unsubscribe endpoint URL (e.g., ``) and/or a mailto address (e.g., ``).
* `List-Unsubscribe-Post`: Set to the literal string `List-Unsubscribe=One-Click`.
***
## Frequently Asked Questions (FAQ)
### How does Smartico track email deliveries, opens, and clicks?
Smartico uses a dual-tracking architecture:
* **Delivery & Bounce Tracking**: When your ESP attempts delivery, it posts webhook events back to Smartico's callback URL. Smartico logs the message status (*Sent*, *Delivered*, *Bounced*, *Dropped*, *Complained*). For specifications on setting up custom status callback endpoints, see [Reverse integration: messaging](/welcome/technical-guides/communication-gateways/reverse-integration-messaging.md).
* **Open & Click Tracking**: Smartico embeds an invisible tracking pixel for open tracking and wraps template links through Smartico redirect endpoints (or your [Branded Links](/welcome/technical-guides/communication-gateways/branded-links.md) domain). For providers that manage open/click tracking natively, the webhook callbacks also synchronize open and click facts into Smartico analytics.
### Can I use different From addresses for different brands on the same gateway?
Yes. When configuring a mail gateway, you can enter multiple From and Reply-To email addresses in the **Options for From & Reply** screen (e.g., `Brand A `, `Brand B `). When building email templates in the Email Template Editor, operators can select the specific From address desired from the dropdown.
### What is the difference between Marketing and Operational From pools?
Smartico separates From address pools into **Marketing** and **Operational** sections within each gateway configuration:
* **Marketing From Options**: Used by default in marketing campaigns, automated journeys, and promotional broadcasts.
* **Operational From Options**: Used for transactional messages (password resets, 2FA codes, account notices). Operational messages can bypass marketing opt-out checks when configured as transactional communications.
### What happens if my ESP credentials or API key expires?
If an API key is revoked or expires, outgoing email activities will fail with gateway authentication errors. Failed attempts are logged in the campaign execution logs and the user's communication history in the Back-Office. Update the gateway settings under **Label Settings → Gateways → Mail** with the new API key to resume sending immediately.
### How can I test a newly configured mail gateway before launching live campaigns?
To verify that a new gateway is functioning correctly before sending communications to players, you can test message delivery in two ways:
1. **Send Preview**: Open any email template in the Email Template Editor, select the new gateway in the sending options, and use the **Send Preview** feature to send a test email to your own address.
2. **Seed Segment Test**: Create a test campaign targeted to an internal seed segment containing verified test accounts, and confirm that emails are received as expected and tracked in the recipient's communication history in the Back-Office.
### What should I do if our preferred email provider is not listed?
If your organization uses an email service provider not currently supported in the catalog, you have two options:
1. **Your Secured Email Gateway**: Connect your in-house sending microservice using our [Secured Messaging Gateways](/welcome/technical-guides/communication-gateways/secured-messaging-gateways-email-sms-im.md) API.
2. **Request Gateway Development**: Contact your Smartico Customer Success Manager or Integration Manager. Our team will analyze the provider's API specifications and build a native adapter.
### How does automatic gateway selection route emails when multiple gateways are configured?
When a campaign or automated communication uses automatic provider selection, Smartico determines the appropriate gateway dynamically at dispatch time:
1. **Brand Matching**: Smartico checks whether any active gateway is restricted to the recipient's brand.
2. **Custom Conditions**: If custom routing properties (such as player country, language, or VIP tier) are enabled, Smartico evaluates them against the player's profile attributes.
3. **Default Gateway**: If no brand-specific or condition-based gateway matches, the email is routed through the gateway marked as **Default Gateway** for the label.
---
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