Setting up a mail service

Email Delivery → Settings → How email leaves. Choose A mail service, then pick yours from the list. The mail server, port and encryption are filled in, and a line under each box says what that service's username and password actually are.

That last part matters more than it sounds. For most of these services the username is not your email address and the password is not the one you sign in with:

• Gmail and Google Workspace — your full address, and an App Password generated in your Google account. Your normal password will not work.
• SendGrid — the username is the literal word apikey, for every account, and the password is your API key.
• Postmark — the Server API token, used as both the username and the password.
• Mailgun, Brevo, SMTP2GO — an SMTP login and SMTP password shown on the service's own SMTP page, separate from your account password.
• Amazon SES — SMTP credentials created in the SES console. Your AWS access key is a different thing and will be refused.
• Microsoft 365 — your address and password, where your administrator still allows that kind of sign-in. Microsoft's own announcement says this password sign-in (Microsoft calls it SMTP AUTH Basic Authentication) is switched off by default for existing Microsoft 365 organisations at the end of December 2026, and is not available by default in organisations created after that. Microsoft says an organisation's administrator will still be able to switch it back on if needed, and that it will announce a date for removing it for good in the second half of 2027. While this site signs in to Microsoft 365's mail server (smtp.office365.com) with a password, on the main connection or the backup, Email Delivery's Dashboard shows a warning saying so, with a link to that announcement. It goes away once no connection signs in there with a password. To keep email going, choose another mail service, or add a backup connection through a different one. Email Delivery does not sign in to Microsoft 365 the newer way (OAuth).

Then set the From address. It must be an address the mail service is allowed to send as — usually one on a domain you have verified with them. If it is not, the service refuses the message and the test will say so in as many words.