Set up ASMTP in Outlook for Windows

These steps are for the classic Outlook that comes with Microsoft 365 and Office. The new Outlook app does not allow separate outgoing server settings for most account types; if you use the new Outlook, see the note at the end.

1. Open Outlook. Click File, then Account Settings, then Account Settings again.
2. Select the email account you want to send through ASMTP and click Change.
3. If you see a screen with "Incoming mail" and "Outgoing mail" boxes, go to step 5. If you see a simpler screen, click More settings (or Repair, then Advanced options, then "Let me repair my account manually").
4. Click the Outgoing Server tab and tick "My outgoing server (SMTP) requires authentication". Choose "Log on using" and enter your ASMTP username and password. Untick "Log on using Secure Password Authentication".
5. On the Advanced tab, set:
   • Outgoing server (SMTP): 587
   • Use the following type of encrypted connection: STARTTLS (called TLS in older versions)
6. Back on the main screen, set Outgoing mail server (SMTP) to smtp.asmtp.com.
7. Click Next or OK. Outlook may test the account. If the test fails on the incoming side, that is your existing mailbox, not us. If it fails on the outgoing side, check the username and password again.
8. Send yourself a test message. Then check your ASMTP customer area: the message should appear in the sending log.

New Outlook (the app with the toggle in the corner): Microsoft does not let you set a different outgoing server for Microsoft 365 or Outlook.com accounts. For other account types, add the account as IMAP or POP and use the settings above. If you are stuck, email us and say which Outlook you have.