Reverse dns for web/mail server with single ip

Reverse dns for web/mail server with single ip

I have a single server with single ip running a web server, mail server
and bind (all for a single domain).
In my DNS zone file I created A records for www.domain.com,
mail.domain.com, ns.domain.com and frog.domain.com ("frog" being my
hostname). All of these records point to the same ip address.
In the reverse zone file I have a PTR record pointing to frog.domain.com
So far so good, but now I am reading that some email spam protection are
doing reverse DNS lookups to check for ip spoofing (as far as I
understand).
Does this mean that I have to change my reverse PTR record to point to
mail.domain.com instead of frog.domain.com in order to pass the spam
filters?
If yes, could this have any negative effect on my web server or DNS?