Providers overview
A relay is an upstream destination Dispatch forwards mail to. You can configure several and pick between them with routing rules. Every provider supports multiple recipients, CC, BCC, text + HTML bodies, custom headers, and attachments.
Supported providers
Section titled “Supported providers”| Provider | Mechanism | Required settings |
|---|---|---|
| Mailgun | REST API (raw MIME) | API Key, Domain, Region (US/EU) |
| SendGrid | Web API v3 (SDK) | API Key |
| Amazon SES | SES v2 API (SDK, raw MIME) | Access Key ID, Secret Access Key, Region |
| Postmark | REST API | Server Token (Message Stream optional) |
| Resend | REST API | API Key |
| SparkPost | REST API | API Key (Region optional) |
| SMTP2GO | REST API | API Key |
| Maileroo | REST API | Sending Key |
| Bird | REST API | API credentials |
| Azure Communication Services | SDK | Connection String, Sender Address |
| Generic SMTP | SMTP via MailKit | Host, Port, Username, Password, TLS mode |
| Local | Capture only | - captures to the Local Inbox; never delivers |
- Raw-MIME providers (Mailgun, Amazon SES, generic SMTP) preserve the original message including arbitrary custom headers.
- Azure Communication Services requires each sender to be a configured MailFrom address; the dashboard test lets you pick from the MailFrom addresses defined for that relay.
- The Local provider is for development and CI - see Local Inbox.