Hi Everyone, My CentOS 4.4 mail server is having problems sending mail after updating it to 4.4 Before the update, I did not have any problems. My ISP requires that email clients must authenticate to their mail servers before mail can be sent out. I setup smtp auth to get postfix to relay mail through the ISP's mail servers. Here's my config: main.cf -------- relayhost = [smtp.broadband.rogers.com] smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = sasl_passwd --------------- smtp.broadband.rogers.com blah at blah.com:password I've done the usual run through of config files after an update, and made some small changes to main.cf (just added in comments and examples that were in main.cf.rpmnew). When I try to send a message, this is the error I get: F060D1C068: to=<m3freak at rogers.com>, relay=smtp-rog.mail.yahoo2.akadns.net[206.190.36.18], delay=1, status=bounced (host smtp-rog.mail.yahoo2.akadns.net[206.190.36.18] said: 530 authentication required - for help go to http://help.yahoo.com/help/us/mail/pop/pop-11.html (in reply to MAIL FROM command)) Just in case the ISP had done something, I manually tested authenticating to the ISP's mail server, and it worked just fine: Connected to smtp.broadband.rogers.com (206.190.36.18). Escape character is '^]'. 220 smtp105.rog.mail.re2.yahoo.com ESMTP ehlo krs 250-smtp105.rog.mail.re2.yahoo.com 250-AUTH LOGIN PLAIN XYMCOOKIE 250-PIPELINING 250 8BITMIME AUTH PLAIN blahblahblahblahblahblahblahblahblah 235 ok, go ahead (#2.0.0) So, the problem is on the Postfix end. I must assume something in the Postfix update broke my setup, but I can't figure out what it is. Has anyone else run into this? Am I missing something obvious? Hints appreciated. Regards, Ranbir -- Kanwar Ranbir Sandhu Linux 2.6.17-1.2142_FC4 i686 GNU/Linux 16:11:07 up 2 days, 9:40, 3 users, load average: 1.06, 0.75, 0.62