April 25, 2004 7:41 PM Subscribe
How does reverse DNS work? [more inside, related to web hosting and anti-spam measures]
posted by malphigian to Computers & Internet (4 answers total)
I have my own leased dedicated server with several sites on it, each with their own IP address. The server also acts as the primary and secondary DNS for each of these sites. I'm pretty comfortable with configuring the DNS and all works swimmingly.
An increasing number of email hosts reject email if there is not a valid reverse DNS lookup, it seems. In other words, mydomain.com name points to 18.104.22.168, but not vice versa, and when the receiving server can't look up mydomain.com from 22.214.171.124, they reject the email.
I did some poking around, and it's apparently impossible for me to set this up, even though I control the primary and secondary DNS server. This is apparently something I need to get my web hosting company to do.
My question is this:
Is that true, and if so, why? Does the owner of an entire ip range (class C? class D?) have to set it up?
Thanks for any help, I'd like to be clear what I'm asking for before I talk to my web host.