Start with the right service
GMX provides a separate setting for third-party access. If the website works but the app cannot connect, check whether POP/IMAP access is enabled and whether the app matches GMX’s current security requirements.
Configuration quick reference
| Reference | What to check |
|---|---|
| Connection and access | IMAP imap.gmx.com:993 SSL/TLS. Outgoing mail.gmx.com:587 STARTTLS or port 465 SSL/TLS as documented by GMX. |
| Account authority | Use the original provider for identity verification, account recovery, eligibility and billing. |
Official reference: GMX IMAP server data. Check the provider’s current instructions before changing settings. Reviewed October 14, 2026.
Work through the problem
- Sign in to GMX through its official website and verify the mailbox is accessible.
- Review the POP/IMAP access option in the mailbox settings before configuring a client.
- Use the full email address and GMX’s current incoming and outgoing settings.
- If a security warning appears, compare the exact certificate or encryption error with official instructions instead of accepting an untrusted certificate.
Keep a useful diagnostic record
Note the exact error, the application and version, and whether the same account works on the provider’s website. Record whether sending, receiving or sign-in fails. Remove private message content from screenshots before sharing them.
If you use POP or local folders, preserve those messages before removing an account. A new account configuration may not recover data stored only on the old device.
Choose your next step
For an app-only problem, compare authorization and settings with the official reference above. For an account restriction or failed identity check, continue with the original provider. Independent assistance cannot bypass these controls.
Related guides: IMAP, POP and SMTP · Password recovery · Email synchronization.