Hi.
Why Whonix connects to port 110? I do not use any e-mail service, use only tor browser.
It’s Tor traffic. Not e-mail. Tor entry guards [or bridges] can listen on any ports.
In the spirit of censorship circumvention, since it helps a bit with connectivity against not very dedicated adversaries, it is a common practice to have Tor relays listen on common ports for web, https, ftp, e-mail, etc.