If the sending of emails through the GMX domain fails, then this may be caused by a blocklisting of the recipient system.
In case of a blocklisting, you will always receive a return mail (bouncer) into your inbox. This return mail contains a detailed description of what exactly happened and why your mail could not be delivered.
Please be aware that returned mails due to a full inbox or an erroneous configuration do not belong to the category blocklisting
.
Through this form you can contact our abuse team to report a blocked GMX server.