When I cat /var/log/qmail/smtpd/current I can see the many entries
where I connected from my laptop while outside the local network, but
there's nothing there that looks like an error or problem. When I
tail -f /var/log/maillog and watch it while I attempt to send from my
laptop, nothing new is appended to the maillog.
If I enable SMTP-AUTH in my e-mail client on my laptop and then try to
send, I can't authenticate, and /var/log/maillog DOES get updated with
the error "vchkpw-smtp: system user shadow entry not found [my
username]:[my laptop's dynamic IP address]" And yet, if I cat
/etc/shadow, I can see the entry for that username.
When using SMTP-AUTH, you username will be your full email address if
its a virtual domain. Your better off sticking to smtp-auth rather than
roaming users, which is pop-before-smtp unless things have changed that
im not aware of.