[Mailman-Users] Help: PTR record and ISP blocking...

[Rodd Ahrenstorff]

I've recently had a local ISP block incoming email from our mailing list
server.  I'm trying to figure out why this occurred.it is not the result of
virus or spam activity.  One thing I noticed:  our PTR record is listed as
mail.domain.org, but it doesn't match the actual host name of the server (as
would be identified in the mail header).  I've now checked the PTR records
for several domains controlled by the ISP in question, and found they don't
include a host name in the PTR record at all.  

 

Otherwise, Mailman has been working perfectly for all other recipients.

 

Questions:

Should I have my ISP drop the host name portion in my PTR?

Could the other ISP be attempting to verify my actual server host name
against the existing PTR record before accepting email?

Any other suggestions to keep the ISP's on my good side? (.beyond the
obvious)

 

TIA,

 

Rodd Ahrenstorff

IT Systems Coordinator

Medical Associates of the Black Hills

rodd at mabhllc.org

Office: 605-718-3150

Cell: 605-209-8912