[Mimedefang] validating 'possibly forged' helo IP's?

[James Ebright]

Actually,. IMHO most ISPs provide some form of rDNS for the IP space 
they maintain... if you have a block from an ISP larger than say a /29 
then I would bet they have swiped the space to you as well... making the 
rDNS setup YOUR responsibility... not theirs.

Some things that do NOT work correctly (or at all in some cases) without 
rDNS for your customers "assuming your an ISP"
FTP
Email
IRC

It is trivial to setup PTR records for any size of IP space, you are 
talking about less than 20 lines of shell code for a fairly complex 
setup, can do it in one typed in for loop if you want.... so there 
really is no excuse to not have any PTR records at all.

Now, if your complaint is they wont customize it.. well... there still 
are some ISPs that believe in customer service, I woudl go find one of 
those :-)

Jim

Gary Funck wrote:

>>ISPs in my experience don't even really care about setting reverse
>>DNS up.
>>    
>>
>
>Isn't it good practice for mail exchanges to have a PTR record?
>I can understand why ISP's don't go to the trouble to rDNS every
>IP in the network, but it would seem to be a good idea to support
>rDNS on their outwardly visible servers.
>  
>