Just a couple of notes as I had the same issues as many others where I received an error when sending.
The solution for me was to add “globalSettings__mail__smtp__trustServer=true” to the global env override
The email then sent and gave me a verification link. That link failed though because it did not contain my HTTPS port override - I used 8444 and the link defaults to 443… No biggie but I haven’t seen that wrinkle mentioned anywhere
Bottom line - after 2 days swearing at vbox networking, certificates and then SMTP configs I now have it up on a virtualbox and reachable from desktop, web and android