Validating incoming mail's return address in Exchange 2003...

9 Apr 2005 1:51 AM

Slippin Through

Not sure if this is the right group to post to. This utility would
reduce the amount of spam I receive along with using SPF. I have found
address validation software to process a mailing list but nothing to
validate at the mail server level. Thanks for any assistance.

9 Apr 2005 2:48 AM

Jim McBee [MVP Exchange]

The company that has my Exchange mailbox uses an SMTP gateway called X-Wall
to validate the incoming mail's DOMAIN NAME, however, it does not validate
the sender's alias. I think that would be pretty difficult, though
possible. SMTP includes a verb called VERIFY that allows a client to verify
if an SMTP address exists or not. However, I don't know of any
implementation of SMTP that actually turns it on. It is turned off in
Exchange and most SendMail servers to which I am exposed.

--
Jim McBee
Web: http://www.somorita.com
Blog: http://mostlyexchange.blogspot.com
Stuff: http://geekbargains.blogspot.com

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"Slippin Through" <U***@INVALIDDOMAIN.COM> wrote in message
news:97de51pqq7fei27houh3eaptrib4nfephp@4ax.com...
> Not sure if this is the right group to post to. This utility would
> reduce the amount of spam I receive along with using SPF. I have found
> address validation software to process a mailing list but nothing to
> validate at the mail server level. Thanks for any assistance.

9 Apr 2005 9:22 PM

Slippin Through

On Fri, 8 Apr 2005 16:48:23 -1000, "Jim McBee [MVP Exchange]"
<jmcbee@cta.spambegone.net> wrote:

>The company that has my Exchange mailbox uses an SMTP gateway called X-Wall
>to validate the incoming mail's DOMAIN NAME, however, it does not validate
>the sender's alias. I think that would be pretty difficult, though
>possible. SMTP includes a verb called VERIFY that allows a client to verify
>if an SMTP address exists or not. However, I don't know of any
>implementation of SMTP that actually turns it on. It is turned off in
>Exchange and most SendMail servers to which I am exposed.

Thanks Jim...I was not aware that most servers don't respond to
VERIFY. Not responding would not return an error message to base logic
on. I know some mail servers will accept all mail and later issue a
NDR. Well, I try to dream up a perfect world.