Just set up postfix & it's running on my RHES 4.2 box.
Immediately after postfix is up, I test sending emails from a permitted domain (ahhh, on this postfix server's domain firewall, we even have a firewall rule which permits Tcp25 from those few sending domains' SMTP servers) using an email client to sender_id@[IP_address_of_the_postfix_server] & the /var/log/maillog on the postfix server indicated the email arrives at the postfix server (with some errors though) :
# grep recipient_id /var/log/maillog* maillog:Feb 15 11:41:52 hostname postfix/smtpd[6891]: NOQUEUE: reject: RCPT from gate1.mds.com.sg[203.126.130.157]: 554 5.7.1 <recipient_id@[202.6.163.31]>: Relay access denied; from=<prvs=020cae8c4=recipient_id@mds.com.sg> to=<recipient_id@[202.6.163.31]> proto=ESMTP helo=<gate1.mds.com.sg> maillog:Feb 15 13:43:20 hostname sendmail[7688]: NOQUEUE: SYSERR(recipient_id): can not chdir(/var/spool/mqueue/): Permission denied
Then I installed dovecot rpm on my RHES box : uninstall it as it's an old version & reinstall with a newer version & start up dovecot as well.
I did not test sending to sender_id@domain_name at that time because the domain I purchased from a domain provider/registrar has yet to be registered in our ISP's DNS. Subsequently I registered the following A, MX & NS records with our ISP :
A: myportaltech.com. IN A 202.6.163.31 A: smtp.myportaltech.com. IN A 202.6.163.31
PTR: 31.163.6.202.in-addr.arpa. IN PTR smtp.myportaltech.com.
MX: myportaltech.com. IN MX 10 smtp.myportaltech.com.
NS: myportaltech.com. IN NS ns1.businessexprezz.com. NS: myportaltech.com. IN NS ns2.businessexprezz.com.
The above myportaltech is just a fictitious name of my domain but I can provide the actual domain name if needed.
After the above records have been propagated to all other DNSes, I test sending email from the same permitted domain, this time using domain name & the email never arrives & I did not receive a 'bounced mail' notification too. Then I test sending from the same domain to recipient_id@[202.6.163.31] & this time round, the test email never show up in /var/log/maillog* anymore.
The network/security guys confirmed that the firewall logs did not show any denied SMTP records.
So how do I go about troubleshooting this?
Is this a DNS record entries issue, firewall/network issue, related to dovecot or something within my postfix server?
Thanks Sun