I'm setting up a new mail server with postfix dovecot and things are working fine except this strange thing. I'm unable to send email to gmail addresses. The log shows status sent. However, I checked there is no email in gmail mailbox.
Jul 8 13:10:08 example postfix/smtp: B53B637C233: to=<email@example.com>, relay=gmail-smtp-in-v4v6.l.google.com[18.104.22.168]:25, delay=2.2, delays=1.5/0.08/0.49/0.14, dsn=2.0.0, status=sent (250 2.0.0 OK 1341727808 nc7si50672387pbc.75)
However, my other account can send to gmail. After several testing, then I found that if I first send email from gmail, then subsequently I can send from my server and email received by gmail.
I don't have this issue with Yahoo. What could be the problem?