This question already has an answer here:
About 8 Month ago, my postfix worked, now it does not work, does my log file look ok?
Aug 21 17:00:34 localhost postfix/master: daemon started -- version 2.7.0, configuration /etc/postfix Aug 21 17:01:11 localhost postfix/smtpd: connect from localhost.localdomain[127.0.0.1] Aug 21 17:01:11 localhost postfix/smtpd: C691694D4F: client=localhost.localdomain[127.0.0.1] Aug 21 17:01:11 localhost postfix/cleanup: C691694D4F: message-id=<email@example.com> Aug 21 17:01:11 localhost postfix/qmgr: C691694D4F: from=<firstname.lastname@example.org>, size=746, nrcpt=1 (queue active) Aug 21 17:01:11 localhost postfix/smtpd: disconnect from localhost.localdomain[127.0.0.1] Aug 21 17:01:12 localhost postfix/smtp: C691694D4F: to=<email@example.com>, relay=gmail-smtp-in.l.google.com[220.127.116.11]:25, delay=0.35, delays=0.05/0.01/0.12/0.16, dsn=2.0.0, status=sent (250 2.0.0 OK 1377118871 f10si5584777qai.16 - gsmtp) Aug 21 17:01:12 localhost postfix/qmgr: C691694D4F: removed
(Note: I changed actual email to: firstname.lastname@example.org)
I did some tracing, results below
$ host -t A smtp.gmail.com smtp.gmail.com is an alias for gmail-smtp-msa.l.google.com. gmail-smtp-msa.l.google.com has address 18.104.22.168 gmail-smtp-msa.l.google.com has address 22.214.171.124 $ host -t MX gmail.com gmail.com mail is handled by 30 alt3.gmail-smtp-in.l.google.com. gmail.com mail is handled by 10 alt1.gmail-smtp-in.l.google.com. gmail.com mail is handled by 40 alt4.gmail-smtp-in.l.google.com. gmail.com mail is handled by 5 gmail-smtp-in.l.google.com. gmail.com mail is handled by 20 alt2.gmail-smtp-in.l.google.com. $
I am pretty new to email, so is it possible that I was black-listed somewhere by any chance?
Edit 8/22/13: OK, got the answer, email can be sent, but email servers will reject it unless criteria is filled, see the link