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Re: incorrect spam setups cause spool messes on forwarders

  • From: Suresh Ramasubramanian
  • Date: Tue Dec 02 10:08:31 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 (postmaster|suresh) // gpg : EDEDEFB9
manager, security and antispam operations