I have postfix and dovecot installed on a Centos 6.4 production (www.bw.co.uk) machine. The intent is to send all system and transactional messages and collect bounces. The email id's that resulted in a bounce are then flagged to prevent site from sending further messages to these id's.
I have the necessary SPF records setup on the DNS and PTR records setup on my hosting providers end. My MX records point to a different mail server where our staff sends and receives email.
My issue is though I have been able to send mail from the production machine I am unable to read bounces using my php snippet. Actually I do not even know if the bounces are reaching the machine!
I have a similar setup on my test (www.st.biz) machine with the same hosting provider the MX, SPF and PTR records are setup in a similar fashion i.e. the MX records point to another mail server where the staff sends and receives mail. On the test machine I am able to read the bounces using the PHP program.
The postfix logs /var/log/maillog on the production machine indicates a single bounce which was not initiated by the php program that send out the transactional messages Mar 3 03:15:03 bw postfix/smtp: 09420120CA3: to=, relay=mail.st.in[999.999.999.999]:25, delay=0.9, delays=0.05/0.02/0.43/0.41, dsn=4.7.1, status=deferred (host mail.st.in[999.999.999.999] said: 451 4.7.1 Please try again later (in reply to DATA command))
Any idea what could be wrong?