On Saturday 09 September 2006 9:19 am, Kjetil Torgrim Homme wrote: > On Fri, 2006-09-08 at 10:45 -0700, Andrew Morgan wrote: > > Otherwise, just let Sendmail queue the message and attempt to deliver the > > message to Cyrus. If the user does not exist, Cyrus will let Sendmail > > know during the LMTP handshake. > > DO NOT DO THIS! if your Sendmail accepts _all_ possible local parts > during the SMTP transaction, you will be sending out lots of bogus > bounces to addresses abused (joe-jobbed) as senders of spam. I second this emphatically. I discovered I was sending out thousands of bounce messages per day with this setup. My solution was to go into my sendmail.mc and define "CYRUSV2_MAILER_FLAGS" to be "A@/:|mw". The default does not have the "w" flag. This flag tells sendmail to validate the user id on the local machine when it queues the mail for this mailer. Since I have a small set of valid users it was easy for me to define them all in /etc/passwd. I'd guess a larger site would want to set up something more complex. The key point is that sendmail still has the connection to the sender open when it selects the mailer. If it detects an error there it responds with an error status to the sending mailer. If no error is detected, sendmail will close the connection before actually invoking the mailer. At this point its only recourse is to send bounce mail. Dave McCracken ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
