[Users] Disable IPv6

[Edward]

On Sat, 16 Jul 2022 08:53:35 +0000
Marco <mo01 at posteo.de> wrote:

> It is not an Ipv6 problem, it is a problem of this server. If you use
> a domain name like imap.example.org there can be an A and a AAAA
> record set. If the AAAA record (IPv6 address) is set, the IMAP server
> service (like Cyrus, Dovecot etc.) MUST also listen on that IPv6
> address on the same port as it does for IPv4. It is a problem with
> that server, so please tell that the server operator.

I am familiar with A and AAAA records. The IMAP server is running
Dovecot and DNS is showing it has has 16 IPv4 addresses. Apart from an
online support forum, there is no direct way to contact the server
admins.

The virtual manager in question has Debian sid (unstable) installed. I
also have Debian bookworm (testing) installed in another VM and Claws
(both version 4.1.0) works perfectly in bookworm. Why it works in one
and not the other, I have no idea.