Gmailify is not available for this provider.

I'm trying to POP or preferably IMAP a Virtualmin Dovecot account.

The first error that appears is 'Gmailify is not available for this provider.'

Fine I move on and chose the only option left 'Import emails from my other account (POP3)'.

I type my email address and password, select SSL and port 995. Then I get this:

"Unable to establish secure SSL connection to xxxx.domain.com"

Server returned error: "SSL error: Leaf certificate is self-signed"

On my server tail -f /var/log/maillog I only see this on each attempt:

Jul 4 10:18:25 vps4900-gxm dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=yyy.85.208.29, lip=zzz.119.250.85, TLS: Connection closed, session=<ruxNwClw+o7RVdAd>

I google "Leaf certificate is self-signed" and only get 10 hits of which 9 seems wrong, but I do get this:

http://openssl.6102.n7.nabble.com/How-to-retrieve-the-certificate-from-r...

I presume I need a lesson on how to self sign certificates? Please direct me I was hoping my fresh server would easily be IMAP/POPable from Gmail :-)

Warm regards, Eugenevdm