During installation I set the HTTPS port to 1443 - the Zimbra installation is behind a NAT'ing firewall, and there are other services port-forwarded to 443. An nmap scan shows the following ports open on the machine:
22/tcp open ssh
25/tcp open smtp
80/tcp open http
110/tcp open pop3
111/tcp open rpcbind
143/tcp open imap
389/tcp open ldap
666/tcp open doom
993/tcp open imaps
995/tcp open pop3s
Nothing interesting in any logs that grep can find...
Visiting
https://my.domain.example:1443/ gets nothing, where
http://my.domain.example/ gets the regular login page (obviously, the actual domain is different).
Any ideas?