[Mimedefang] Checking for a valid sender
Alan Madill
amadill at hwy16.com
Tue Nov 18 12:50:31 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.)
I've gone through the man pages and I know what it was intended to
do.
The reason that we have a spam problem to begin with is the SMTP
protocol wasn't designed to deal with it. What is needed is a new
protocol or an extension to SMTP that does...
Verify that the sender is real. (there goes 90% of your spam).
Built in white/black-listing (content management on the remaining
10%)
Encrypted transfers.
That is the short list. I'm sure you can think of other extensions.
--
Alan Madill - Aspen House Systems
250 567-4200
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