GMX Mail Login and Sending Problems

Applies to: GMX Mail web, GMX Mail app

Quick answer: Use password recovery rather than retrying, enable IMAP/POP access under Settings before adding the account to a third-party app, and generate an app password if two-factor authentication is on.

Missing incoming mail instead? See our guide on GMX Mail not receiving emails. This one's about signing in and sending.

1. Can't sign in

  1. Confirm you're using your full address, including whichever domain you picked at signup — GMX offers several, and mixing them up is an easy mistake to make.
  2. Use password recovery instead of retrying repeatedly, which can trigger a temporary lock.
  3. Try a private window if the login page itself seems stuck.

If signing in keeps redirecting you straight to GMX's Help Center page instead of loading your inbox, that's a specific, recognized pattern many users report rather than something wrong with your particular account — clearing cookies for gmx.com and retrying sometimes clears it, but if it persists across multiple attempts and devices, it may be a wider issue on GMX's side rather than anything fixable through your own settings.

2. Third-party app won't sign in

GMX requires POP3/IMAP access to be explicitly turned on before third-party apps can connect at all.

  1. Sign in to GMX Mail on the web.
  2. Settings → POP3 & IMAP → confirm the protocol your app uses is enabled.
  3. Two-factor on? Generate an app-specific password rather than using your normal one.

If a third-party app (Outlook, Thunderbird, or another mail client) that used to connect fine suddenly starts rejecting your password with an authentication error, even though webmail itself still works — that's consistent with GMX periodically tightening its login requirements for POP3/IMAP/SMTP access. An app-specific password is the fix in almost every case I've seen reported; your regular GMX password quietly stops being accepted for these connections even without 2FA changing on your end.

3. Emails stuck in the Outbox or rejected

  1. Check for an oversized attachment — GMX's limit runs smaller than a lot of other providers.
  2. Third-party app? Confirm outgoing settings: mail.gmx.com, port 587 or 465, authentication required.

4. Account flagged or sending restricted

Free webmail accounts sometimes get temporary sending limits after unusual activity or high volume, as an anti-spam measure. If sending suddenly stops with no clear error, waiting a few hours is often the actual fix, not a settings change.

GMX will never ask for your password by email. Treat "your account will be closed unless you verify" messages as suspicious, and go directly to gmx.com instead of clicking through.