Threading the senderbase reputation needle

Drew Weaver drew.weaver at
Tue Feb 2 15:32:46 UTC 2010

Since email reputation is now being based on the neighborhood theory you
must do one of the following:

Do one of the following (hopefully #1):

1.) Provide custom reverse DNS for the customer.  BCP for SMTP server DNS
is matching forward and reverse DNS.  Anything else is suspect...

2.) Set up a relay host and funnel all customers mail through it.

Side effects of each:

1.) Slightly more work on the front end (but hey, even AT&T will do this
for business DSL customers).  People will know you have clue.  The
technical staff at your customers will be happy and recommend you to their
peers (well, I guess this depends a bit on what kind of customers you

2.) You have taken responsibility for all your customers' outbound mail
flows.  You will need to scale an abuse desk and maintain effective
anti-spam policies (including customer education).  If you don't run an
effective abuse desk (including blocking your own customers outbound mail
when necessary), you will be blacklisted eventually anyway.  You could
charge extra for or outsource this ESP service.

Okay, as I mentioned, we allow the customers to set their reverse DNS to whatever they want as long as the forward and the reverse match. we don't own the customer's domains nor do we host the DNS for 99% of them, so I'm not sure how we could enforce a rule saying that everyone on our network has to have their reverse DNS set a certain way. That is why we set it up like we did, because we can control hostnames within our domain and we can set the PTR record to match. Like I said before we're a hosting company, we sell Co-Lo, Dedicated servers, and Virtualization products. 

It seems somewhat impossible to employ either of your suggestions in our environment.


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