In the popular Fritz!Box 7272 from AVM there is a Push Service function, which can be used to receive status and usage data from the Fritzbox. To do this, it is necessary to enter your own SMTP server with a valid e-mail account.
It only becomes problematic if the domain ending of the mail server is one of the new Top Level Domains with more than 6 characters, e.g. the .network . In this case the Push Service function cannot be used because the Fritzbox checks the length of the TLD and rejects all extensions with more than 6 characters.
The problem has been forwarded to the development department and may be solved in one of the next Updates can be fixed.
With the new Domain-endings, many large providers have their problems.