[Mimedefang] Checking for a valid sender

David F. Skoll dfs at roaringpenguin.com
Tue Nov 18 10:12:19 EST 2003

On Tue, 18 Nov 2003, Alan Madill wrote:

> A large percentage of spam has a fake from address.  Has anyone
> tried using md_check_against_smtp_server to test the senders
> address?

No, and don't you try it!  md_check_against_smtp_server is designed to
check the validity of a _recipient_ address.  There is no practical way
to verify the existence of a _sender_ address (other than very mild tests
like ensuring the domain has a valid MX or A record.)

Any mail I send to you will come from the machine  However,
you cannot connect to on port 25, because our incoming mail
takes an entirely different route.



More information about the MIMEDefang mailing list