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: NOQUEUE: reject: RCPT from gate1.mds.com.sg[18.104.22.168]: 554 5.7.1 <email@example.com>: Relay access denied; from=<firstname.lastname@example.org> to=<email@example.com> proto=ESMTP helo=<gate1.mds.com.sg>
maillog:Feb 15 13:43:20 hostname sendmail: 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 22.214.171.124
A: smtp.myportaltech.com. IN A 126.96.36.199
PTR: 188.8.131.52.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
firstname.lastname@example.org & 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 or something
within my postfix server?