Send button doesn't send

I just installed Mailspring. I typed my first message this afternoon, and when I pressed SEND, nothing happened. I am using my Fastmail account, and the install went fine. I can definitely read all the mail in the account, but I can’t send any. Thanks for your help!

If clicking Send does nothing, this is almost always an SMTP configuration issue — the send is failing silently. Here are a few things to try:

  1. Check Preferences > Accounts, select your Fastmail account, and look for any error message or red indicator on the SMTP settings.
  2. Make sure your Fastmail account is configured with an app password — Fastmail requires app-specific passwords for IMAP/SMTP access. You can generate one at app.fastmail.com/settings/security/tokens.
  3. Check that SMTP is set to smtp.fastmail.com, port 465, SSL/TLS, with your full email address as the username.
  4. After updating, try sending a test message to yourself.
    If the issue persists, check the logs at Help > Mailspring Logs for any SMTP error details.