Andrew Morgan wrote: > On Sat, 9 Sep 2006, Dave McCracken wrote: > >> 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. > > To my knowledge, Postfix does not support the socket map protocol for > verifying a mailbox exists during the SMTP transaction. I guess the > Postfix users are just screwed on this then. :) > > In our case, our campus mail relays (6 of them currently) accept mail > for all domains on campus and perform RBL and spam tagging before > relaying the messages to their final destinations. You'll have to live > with the bounce messages coming from our domain. :P > > Andy Hi Andy! Hi Dave! I stated this in my last mail already: If the cyrus users are in a mysql database, then postfix with mysql support CAN verify if mailbox exists. > cat /etc/postfix/mysql-mailboxes.cf # # mysql config file for local recipient maps lookups on postfix # comments are ok. # # the user name and password to log into the mysql server # hosts = unix:/var/lib/mysql/mysql.sock localhost hosts = unix:/var/lib/mysql/mysql.sock user = XXXXXXX password = XXXXXXX # the database name on the servers dbname = mail # the table name table = virtual select_field = alias where_field = alias ---- 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
