I would like to operate an incoming-only MDA (Mail Delivery Agent) server mail for domain xyz.com on an Ubuntu server hosted behind my ISP (Internet service provider) Comcast. The objective is to receive firstname.lastname@example.org and potentially reject (not bounce) spams. I don't intend to have any SMTP server on this machine.
Reverse DNS for Comcast gives me: c-XXX-XXX-XXX-XXXX.hsd1.ca.comcast.net and I guess that as a home user, I will never be able to point this reverse DNS to the domain name.
http://whatismyipaddress.com/blacklist-check reports all OK for this IP address except one for spamhaus.org. IP is listed in PBL as explained here: http://www.spamhaus.org/pbl/query/PBL1523090. I have understood that it's not a catastrophic situation and it can be fixed.
Question: is this a problem to have a reverse DNS pointing to a domain address that is different from the domain for which the mail server is operating? Would some SMTP server refuse to send email to my MDA because of that?