GMX Not Working? Common Fixes

GMX problems fall into a few recognisable shapes: mail not arriving, mail refusing to send, a mail program that will not connect, or messages that seem to have vanished. This guide works through each — starting with something GMX documents that explains one of the most maddening behaviours in the whole service.

Mail is not arriving

Check your filter rules first — they beat the spam filter

This is the one worth knowing, because it explains behaviour that otherwise looks like a fault.

GMX processes your filter rules before your personal spam filter. A rule always wins. So if you have a rule that files mail from a particular sender into the Inbox, marking their messages as Spam will do nothing at all — the rule has already decided, and no amount of repeating the marking changes it.

It works the other way too. A rule sending someone's mail to the Spam folder keeps doing so no matter how often you mark it Not Spam.

If a sender is persistently landing in the wrong place, open your filter rules and look for one covering that address. Editing, deactivating or deleting the rule is what actually fixes it.

Rules are also worth auditing generally: one written years ago for a newsletter can quietly swallow mail matching a pattern you have long forgotten, including messages you now want.

Check the Spam folder — and train the filter properly

Spam Protection is switched on by default, under Email → Settings → Mail Security. Legitimate mail lands there sometimes.

Marking a message Not Spam adds the sender to your allowlist so future mail arrives in the Inbox. Marking one Spam adds them to your blocklist.

Spam-filter training works through GMX webmail and the official GMX Mail app. Marking a message as Spam or Not Spam in either official interface helps GMX classify future messages from that sender.

Moving a message in a third-party client such as Outlook, Thunderbird or Apple Mail changes the message’s folder but does not train GMX’s personal spam filter. If you use POP3, configure the program to leave copies on the server so the messages remain available in GMX webmail or the official GMX Mail app for correction.

Two settings worth knowing about while you are in Mail Security. You can have mail from anyone in your Contacts always delivered to the Inbox — useful and quick. And you can reset the spam filter entirely if it has been trained badly, though that deletes all previous training and starts it over.

Check your storage

A full mailbox stops mail arriving, and GMX names lack of storage space as a cause of bounced messages — meaning senders get an error rather than their mail waiting for you.

Clear space by deleting large attachments, then empty the Trash. Be careful there: GMX is explicit that deleting from Trash is permanent — the contents are gone forever.

Check where you are actually looking

Before concluding anything is lost, check the Spam folder, the Trash, and any custom folders. If you use a mail program on another device, remember that with IMAP a deletion or move there is reflected everywhere — so mail "missing" from your inbox may have been filed by a phone you had forgotten was connected.

Mail will not send

If a message bounces back with a mailer-daemon error, read the code rather than the wording — GMX explains what the ranges mean, and the distinction is genuinely useful.

• 400-range: temporary. In most cases the message will be delivered eventually. Usually nothing to do but wait.

• 500-range: permanent. It will not be delivered under any circumstances, and something has to change before it can be.

For a 500-range bounce saying something like "mailbox unavailable" or "unknown user", check the recipient's address for typos. That accounts for most of them.

If your mail is being treated as spam

A more awkward bounce says the receiving system blocked your message due to the low reputation of the sending IP address. That means GMX's own filters classified your outgoing mail as spam and routed it through servers used for suspected spam — which the recipient then rejected.

GMX names common triggers, and they are easy to fall into innocently:

• Using a VPN that many spammers also use.

• Link shorteners or tiny URLs in the message body.

If your mail is being rejected this way, try sending without the VPN, and replace shortened links with full ones. Both changes cost nothing and frequently resolve it.

A mail program will not connect

The first thing to check is not the password.

GMX switches POP3 and IMAP off by default. Until you enable external access in your GMX settings, no mail program can connect regardless of what you enter. Our server settings guide covers turning it on and the hostnames you will need.

After that, in rough order:

• If two-factor authentication is enabled, use an application-specific password instead of your normal GMX password in the external mail program. Check that the application-specific password is saved in both the incoming and outgoing account settings. See our GMX Security guide for setup instructions.

• The program may be too old. GMX requires TLS 1.2 or 1.3 and no longer supports 1.0 or 1.1. An outdated program reports this as a credentials failure.

• Security software — antivirus or firewall mail scanning — can block the connection with no error from GMX.

• Check the error on the website. GMX's own advice: some errors, such as temporary blocks, cannot be displayed properly by a mail program. Sign in at gmx.com on a computer and the real message appears with instructions.

Duplicate Trash and Junk folders

If your mailbox has sprouted extra folders, this is why: many email programs cannot correctly link their own folders to GMX's system folders — their recycle bin might be called "Trash" where GMX names it differently — so the program creates the missing folder instead.

The fix is in your mail program rather than in GMX: set the folder mapping manually in the account settings so Sent, Drafts, Trash and Spam point at GMX's existing folders. Then delete the duplicates.

The website is slow, blank or misbehaving

Try a private or incognito window. That single test separates a browser problem from an account problem.

• Works in private browsing: a stale cookie or an extension is the cause. Clear cookies for gmx.com, and try with ad blockers and privacy extensions disabled.

• Fails there too: try another browser or device before assuming an account problem.

Beware of fake GMX support numbers

Search results for GMX problems may include third-party pages displaying supposed support phone numbers. Treat any number that is not published on a GMX-owned website as unverified and potentially fraudulent. Use GMX’s official Help Center and the contact options available through GMX itself.

They work by catching people at their most frustrated. The "agent" asks for a verification or reset code, and with it takes the account permanently.

Two rules keep you safe. Only use contact information published on an official GMX-owned website. And never read a code aloud to anyone, for any reason.

Narrowing it down

Rather than changing settings at random, answer these first:

• Does it fail on the website too, or only in a mail program? Only in the program means connection or authentication. Both means the account.

• Can you send but not receive, or the reverse? That alone halves the possibilities.

• Is it one sender, or everyone? One sender points at a filter rule or the spam filter. Everyone points at storage or access being switched off.

• Did it stop suddenly or gradually? Sudden suggests a change — a password reset, a new rule, an update. Gradual suggests storage filling up.

Two minutes on those beats an hour of changing things, and avoids the common trap of fixing something that was never broken.