[Cialug] PTR records & SPF?

[Dave Weis]

> > No, a given IP can only have one name returned for reverse DNS.
> >
> Actually, multiple PTR records *are* legal, .. but very 
> uncommon and often break resolvers.

I know they are but so is kissing your sister, you just shouldn't do it :-)

> > Just make sure the HELO matches the reverse and you should be fine.
> >
> Always done that, .. but I'm trying to respond to a hosting 
> company that claims the reverse DNS name does not have to 
> match the HELO.

It doesn't strictly have to but I generally do so.

> > We have hundreds of domains where the MX doesn't match the hostname 
> > but there is a matching set of forward and reverse.
> >
> So the MX doesn't match the helo, rather it's a common 
> outbound server with valid forward/reverse entries?


One of our virtual mail servers is named strange.internetsolver.com. It's forward and reverse match it's IP's. It's externally referred to as mail.ishsi.com however. Lots of domains point to mail.ishsi.com for their MX. 

Dave



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Dave Weis
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