incorrect spam setups cause spool messes on forwarders

Tue Dec 2 15:05:34 UTC 2003

Richard Cox  writes on 12/2/2003 9:57 AM:

> VRFY is an (unavoidable) part of the checking routine built into the
> popular "Sam Spade for Windows" client, for manual verification of any
> suspect addresses found to have sent suspicious mail.  So just looking
> for VRFY can give you some, er, false positives there ;-)

"a stream of vrfy / expn" I should have said.

> Implementing DELAY_CHECKS (which is normal anyway these days) will of
> course make a complete mockery of the process Verizon have implemented.

Say again?  All that delay_checks in sendmail (and this is the default 
in exim / postfix etc) does is to defer any rejects based on IP / sender 
domain etc till the RCPT TO stage instead of returning 5xx at MAIL FROM: 
itself.

I don't see how or where this will have an impact on verizon's sender 
verify.

cf/README for sendmail says -

> delay_checks    The rulesets check_mail and check_relay will not be called
>                 when a client connects or issues a MAIL command, respectively.
>                 Instead, those rulesets will be called by the check_rcpt
>                 ruleset; they will be skipped under certain circumstances.
>                 See "Delay all checks" in the anti-spam configuration control
>                 section.  Note: this feature is incompatible to the versions
>                 in 8.10 and 8.11.

	srs

-- 
srs (postmaster|suresh)@outblaze.com // gpg : EDEDEFB9
manager, outblaze.com security and antispam operations