Re: [Exim] sender callout failing

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Author: David Saez
Date:  
To: Exim Users Mailing List, woods
Subject: Re: [Exim] sender callout failing
Hi !!

> To the extent that active sender address testing is worthwhile it must
> only be done with "<>" as the test's sender address. Think about it.
> Why do you want to verify the validity of a sender address? When is the
> sender address used? What sender address "MUST" be used when the
> sender address under test becomes a recipient address?


I mainly want to test the addresses as most spammers use inexistent
return addresses. It will cut almost 20% of all received spam, but i
cannot use it for that purpose as some non spam emails come with email
addresses in the header (mainly From:) where the mx for the
corresponding
domain does not accept null envelope senders. I don't need to test that
condition, I only need to test if the address exists or not.

> A server that won't accept bounce messages _is_ broken and _all_ sender
> addresses routed to that server are, _by_definition_, invalid!


no, the server is broken, but it can receive email for valid addresses.

> > but maybe it will
> > be better to relax it when testing addresses from the header.
>
> Perhaps -- it all depends on why you're doing the testing, i.e. what
> policy you are trying to implement.


spam control.

> Note that actively testing addresses from headers is very unlikely to
> ever have any valid purpose and _will_ break many other things in many
> very unexpected ways.


I've testing header addresses with callout (by now just adding a
special header line to failing ones) and it does not break nothing,
it just flags a lot of spam and some valid emails.

--
Best regards ...

I need my computer; it keeps me out of the bars!!

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