We divided our outbound email into two streams: transactional and
bulk. Each of the streams uses different ip addresses. One ip for
transactional email and a randmap group of four ips for bulk email.
The transactional email is sent from domain @raystedman.org. The bulk
email is sent from a subdomain @devotion.raystedman.org.
The ip addresses used for all of our outbound transfers are configured
using raystedman.org for both forward and reverse DNS. For example,
if one of the bulk hostnames is t4.raystedman.org pointing to 1.2.3.4.
Dig -x 1.2.3.4 (reverse dns) points back to t4.raystedman.org. The
master.cf transports are configured with:
-o smtp_bind_address=1.2.3.4
-o smtp_helo_name=t4.raystedman.org
I believe this is a fairly standard setup for the domain.
We are receiving a few entries in our maillogs that look like this:
Oct 23 02:04:12 mail0.raystedman.org t4/smtp[38639]: C422783FDAA:
to=<em...@prodigy.net>,
relay=al-ip4-mx-vip1.prodigy.net[144.160.235.143]:25, delay=3.7,
delays=0.04/0/3.6/0.02, dsn=5.7.1, status=bounced (host
al-ip4-mx-vip1.prodigy.net[144.160.235.143] said: 550 5.7.1
Connections not accepted from servers without a valid sender
domain.alph765 Fix reverse DNS for 1.2.3.4 (in reply to MAIL FROM
command))
We saw five of these maillog entries last night (out of 32K emails
sent) all from prodigy.net. This results in not delivering the bulk
email and a "soft bounce" for the email address recorded in our
database.
Should we reconfigure our bulk ip addresses using the subdomain
devotion.raystedman.org? If we do, the bulk from address
@devotion.raystedman.org will match the end of the reverse DNS of the
IP address.
Change the hostname of each bulk ip address to use the subdomain
Change the reverse DNS for each bulk ip address to point to the new hostname
Update master.cf transports to use the subdomain -o
smtp_helo_name=t4.devotion.raystedman.org
Is this the correct solution? Is there something else we should
consider? I am being cautious as we will need to make this change on
the production system. If we implement this, I hope this transition
will go smoothly with all of the relays we are using to deliver the
bulk email. Perhaps we will change only one of the bulk ip addresses
initially and observe the maillog. Advice and counsel is welcome!
Thanks, Greg
www.RayStedman.org
