Reverse Dns Question...is it really necessary or not?

[Jason Gurtz]

Just to set the record straight, AOL does not outright block email (as
some others do) from MXs with no PTR record.  They do, however, count it
as a strike against the MX.  Additionally, they will not grant whitelist
status unless your MX has a PTR.  In AOL's case the PTR record need not
perfectly match the corresponding A record, it's enough just that one
exist for that IP.

This means that most will be ok using just the generic PTR records as
assigned by their upstream ISP.  I found that even our highly
bureaucratic ISP (SBC Inc.) was willing to assign generic PTR addresses
for our net blocks (it did take a little pushing).

More info can be found at <http://postmaster.aol.com/>

It's a fact that postmasters applying stricter policies then AOL WRT PTR
records are blocking mail from a great number of small businesses as
well as legitimate mail from third world countries with recalcitrant
ISPs.  This is their right.

Having a reverse record mostly means that a receiving MX can find a
responsible domain for the sending MX's IP addy without resorting to
whois.  Like other people have said, this will only be more prevalent as
time goes on.

Cheers,

~Jason

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