[Users] Disable IPv6

[Marco]

Am Sun, 17 Jul 2022 15:24:26 +0200
schrieb Paul Rolland <rol at witbe.net>:

> You are making a test with tcp port 25. This is definitely NOT Imap,
> and it may explain the Connection refused...

ok, my fault, the TO should try all these addresses with Port 143
(normal IMAP) and IMAP over TLS (993).
Connection refused must not occur then if both imap/imaps is supported.
I tried some, for me it works, so it is not a problem with IPv6.

Disabling IPv6 is not the solution here.