Hi, all. I went though the Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail and everything seems to work fine. My setup should be exactly the same as the howto. It's a great howto. Even though everthing is working fine, email sending and recieving, I took a look at /var/log/maillog and found some suspecious lines. I checked with the Open Relay Checker at MxToolbox (http://mxtoolbox.com/diagnostic.aspx) and came back negative. Also, checked if my IP has been blacklisted, it's not. Here's a sample. Please let me know what you think. FYI, I slightly modified the urls, IPs, and time stamps. Code: May 29 12:00:00 myserver postfix/smtp: 8DFDXXXXD5: to=<operator603@msbraininjuQWERTYrylawyers.com>, relay=none, delay=65764, delays=65734/0.02/30/0, dsn=4.4.1, status=deferred (connect to mail.msbrQWERTYaininjurylawyers.com[126.96.36.199]:25: Connection timed out) May 29 12:00:00 myserver postfix/smtp: 6EBXXXX7D7: to=<operator961@blbQWERTYlawyers.com>, relay=smtp.secureserver.net[188.8.131.52]:25, delay=3.8, delays=0.01/0.01/3.7/0.08, dsn=5.1.0, status=bounced (host smtp.secureserver.net[184.108.40.206] said: 550 5.1.0 <> Blank From: addresses are not allowed. Please provide a valid From: IB501 <http://x.co/srbounce> (in reply to MAIL FROM command)) May 29 12:00:00 myserver postfix/smtp: F0AXXXX078A: to=<noreply130@contractQWERTYlitigationlawyers.com>, relay=none, delay=172707, delays=172677/0.02/30/0, dsn=4.4.1, status=deferred (connect to nlmx1.ca.einsteinindustries.com[220.127.116.11]:25: Connection timed out May 29 12:00:00 myserver postfix/smtp: connect to nlmx1.ca.einsteiniQWERTYndustries.com[18.104.22.168]:25: Connection timed out May 29 12:00:00 myserver postfix/smtp: 044XXXX07D7: to=<customerssupport537@rwlaQWERTYwyers.com>, relay=mx01.263xmail.com[22.214.171.124]:25, delay=1.7, delays=0.01/0.01/0.85/0.84, dsn=5.0.0, status=bounced (host mx01.263xmail.com[126.96.36.199] said: 550 customerssupport537@rwlaQWERTYwyers.com:user not exist (in reply to RCPT TO command)) The urls are related and can be within a couple seconds of eachother. A couple hundred, similar to the sample, over the last few days.