[SOLVED] Received: from in mail header has wrong IP

mfoley · 09-15-2022, 11:27 AM

I am sending email from novatec-inc.com, public IP 24.142.169.12. However, when I send an email from this host, the Received: header is:

Code:

From mfoley@novatec-inc.com  Thu Sep 15 12:15:40 2022
Return-Path: <mfoley@novatec-inc.com>
Received: from server (rrcs-24-142-169-10.central.biz.rr.com [24.142.169.10])

I've never seen this happen before. the .10 IP is a completely different computer with a completely different domain. How is an email from .12 getting sent with a Received: of .10?

I am using sendmail 8.15.2. There is no SMART_HOST specified in my .mc file. This IP is nowhere to be found on this host.

This is a new IP for this server. Previously it was on a dynamic IP.

Since getting the new IP I have been having multiple problems with email. I'm wondering if this funkiness in the Received: header could be part of the problem.

Is this something in some config on my end somewhere, or could there be a mess-up on the ISP's end?

How do I go about fixing this?

baldur2630 · 09-15-2022, 04:58 PM

I had a similar problem a while back I battled for days trying to find the problem. Finally I did a grep on /etc and it was a damn typo in resolv.conf. It's hard to spot.

mfoley · 09-16-2022, 02:31 PM

Although not originally related, this problem got solve in thread https://www.linuxquestions.org/quest...en-4175716742/. Similar to you. A combination between resolv.conf and rc.inet1.conf USE_DHCP. I'm not entirely sure about what actually caused it, but I did set settings in those file that untimately fixed it. In particular, I had to explicitly set USE_DHCP[0]="no" and make sure the resolv.conf nameservers stuck (they kept getting clobbered by dhcpd).

baldur2630 · 09-16-2022, 02:33 PM

Glad you found it.