GMX, WEB.DE and mail.com · temporary error

450: E-Mail Made in Germany requirements not met

GMX rejected the connection because it did not meet the requirements of E-Mail Made in Germany (EMiG), usually because of missing or inadequate encryption.

GMX, WEB.DE
Provider: Temporary (4xx)
Class: 20 Oct 2026
Sources checked: By Frank, email deliverability consultant
Author

At a glance

Code: 450
Provider: GMX, WEB.DE and mail.com
Temporary or permanent: TemporaryThe sending server keeps the message and tries again later.
Who has to act: The sender. The fix is on the sending side: your domain, your server or your list.
What the server says: 450 Insufficient security or privacy level

What it means

E-Mail Made in Germany is an initiative of German mail providers, GMX and WEB.DE among them, that requires mail between members to travel encrypted. Case r1901 means a connection fell short of its requirements, so GMX refused it with a temporary 450. The case page names two likely reasons: encryption that is wrong or does not meet the standard, and an MX DNS setup that does not match the EMiG specifications. Check the TLS configuration of your mail system and its MX records against both points.

Common causes

Your server did not use TLS, or used a version or cipher GMX does not accept for EMiG.
The TLS certificate does not fit the server name or is not valid.
Your MX records do not match what the EMiG specifications expect.

How to fix it

01Enable STARTTLS on outbound connections with current TLS versions and ciphers.
02Install a valid certificate for the host name your server uses.
03Review your MX records against the EMiG requirements.
04Let the message retry once the configuration is fixed.