I've been having fun w/ smtp-auth-proxy on 6.5RC2. I need to get this going for sbc as well - a major PITA. Anyways, I started out with smtp.sbcglobal.yahoo.com entered in "Address of Internet provider's mail server" in the server-manager.
Then I followed meanlocha's instructions above to add SMTPSmartHost, Userid, & Passwd.
Still am not able to auth. I get the following error in response to outgoing test mail and in /var/log/qmail/current:
"Remote host said: 530 authentication required - for help go to
http://help.yahoo.com/help/us/sbc/dsl/mail/pop/pop-11.html"
I do a "netstat -nlt inet" and see, as expected:
tcp 0 0 127.0.0.1:26 0.0.0.0:* LISTEN
which means smtp-auth-proxy is at least running.
I check /var/qmail/control/smtproutes, which has the following entry
:smtp.sbcglobal.yahoo.com
This doesn't make sense -as I understand it- the entry should be
:127.0.0.1:26
to forward all remote bound mail to the smtp-auth-proxy, which then forwards to smpt.sbcglobal.yahoo.com. sbcglobal in smtproutes would cause qmail to directly try to comunicate with that server, which bypasses smtp-auth-proxy!
If I manualy change the smtproutes to ":127.0.0.1:26", my outgoing mail properly gets passed to smtp-auth-proxy -> smtp.sbcglobal.yahoo.com -> destination smtp server.
So is this a bug, a feature, am I missing something, or have I cheated?

Irregardless, hope this helps someone else out...
David Lemstra