Hello all,
I am using the following in the check_recipient acl to
verify sender addresses:
require message = Unable to verify sender address
verify = sender/callout=30s/callout_defer_ok
It works fine, and the overhead seems worth the number
of unverifiable spam-like sender addresses that fail
verification.
Lately though I have been running into more and more improperly
configured hosts that behave like this (this is the most latest):
[root@mail]# telnet cmswww1.imr.tohoku.ac.jp 25
Trying 130.34.224.202...
Connected to cmswww1.imr.tohoku.ac.jp.
Escape character is '^]'.
220 cmswww1.imr.tohoku.ac.jp ESMTP Sendmail 8.11.0 ready at Tue, 1 Oct 2002 23:53:29 +0900 (JST)
helo engineering.ucsb.edu
250 cmswww1.imr.tohoku.ac.jp Hello mail.engr.ucsb.edu [128.111.53.8], pleased to meet you
MAIL FROM:<>
553 5.7.1 <>... Domain part missing
The address verification probably would have succeeded had it not been
for their apparently non RFC821-compliant configuration. I've this occur
with a number of different server applications in addtion to sendmail.
Contacting the postmasters for the sites is often futile.
Would it be practical to have an option on sender/callout which
caused verification to be considered successful if the response to
"MAIL FROM:<>" was 5xx? I realize it is not optimum, but I can't
think of another good way to both maintain sender/callout verfication
while accepting mail from these hosts.
Thanks,
Tom
========================================================================
Tom Marazita, Manager ECI Systems | Engineering Computing Infrastructure
| 3110 Engineering 1
toad@??? | University of California
voice: 805 893-3221 | Santa Barbara, CA 93106-5120
========================================================================
