Received from peter.sayer@... at 9/24/2018 08:02 PM UTC:
Failed - 550 5.7.1 <user@...>... PTR-listed: Mail from your subnet is rejected. Contact abuse@... to have this matter resolved. (IP: 66.175.222.12)
...
Any thoughts on what might be done to remediate the reputation of the sending server? For now our first line of attack is to ask the two users concerned to use their home, rather than work, email address; the next will be to write to the abuse addresses and beg. ;-)
Writing to the abuse address is the solution, but the domain given - domains.in.question - isn't routable over the Internet. It may be a domain local to the academic institution's network... which means your prospective members should complain... and if that complaint address doesn't work, then they can try
postmaster(at)the_academic_domain and/or abuse(at)the_academic_domain .
Jim H
