Backends send mail through a mail account that you store for the organization under Connections; the connection types appear together in projects in the Mail account picker.
Mailtrap, Resend, SendGrid, or generic SMTP
Mailtrap, Resend, and SendGrid are the recommended options when the provider offers a single API token for sending and domain management. You store only the token and, optionally, a sender name and sender address; MainPath sends through SMTP and shows status and your sending domains with DNS checks in the detail view, where you also create new sending domains.
Email (SMTP) is a generic SMTP account with host, port, username, password or API key, sender address, and sender name for any other provider.
SMTP, IMAP and co. explains how SMTP differs from IMAP and POP3.
Flow with Mailtrap, Resend, or SendGrid
- Create an API token at the provider, as described under SMTP with Mailtrap, SMTP with Resend, or SMTP with SendGrid.
- Under Connections, use the matching tile to create a connection with that token.
- Verify your sending domain with the DNS records from the connection’s detail view.
- Select the connection in the project as the Mail account; the generated backend reads the credentials from its configuration.
Flow with generic SMTP
- Create an account with your email provider and note the host, port, username, and password.
- Under Connections, use the Email (SMTP) tile to create an entry with those values plus the sender address and sender name.
- Select the connection in the project as the Mail account.
Locally, mp run-local also starts Mailhog for backends, which shows outgoing mail in the browser.
Keep credentials narrow
Use API keys, tokens, or app passwords from the provider instead of your personal login, and restrict the account’s permissions to sending.