Mailing List Archive: Verify sender callout uses wrong HELO data

Verify sender callout uses wrong HELO data

Aug 12, 2006, 1:22 PM

Post #1 of 3 (1172 views)

When Exim 4.63 performs a verify sender callout, it picks up the interface
and port from the SMTP transport (calling code in smtp_out.c), however
it uses smtp_active_hostname for HELO data instead of picking up the
transport's helo_data. Some remote mailservers notice that the HELO
data hostname doesn't match the connecting interface.

The suspect code is in verify.c lines 413 through 476.

Steve

----------------------------------------------------------------------
Steven A. Reisman <sar@pressenter.com> P.O. Box 409
Press Enter LLP 421 N 2nd Street
715-426-2100 or 651-436-5254 River Falls, WI 54022
----------------------------------------------------------------------

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Re: Verify sender callout uses wrong HELO data [ In reply to ]

ph10 at hermes

Aug 14, 2006, 1:17 AM

Post #2 of 3 (1135 views)

Permalink

On Sat, 12 Aug 2006, Steven A. Reisman wrote:

> When Exim 4.63 performs a verify sender callout, it picks up the interface
> and port from the SMTP transport (calling code in smtp_out.c), however
> it uses smtp_active_hostname for HELO data instead of picking up the
> transport's helo_data. Some remote mailservers notice that the HELO
> data hostname doesn't match the connecting interface.
>
> The suspect code is in verify.c lines 413 through 476.

There is an item on the wish list to re-implement callouts so that the
code in the smtp transport is used directly, instead of having to fish
things out of the transport as now. Whether/when this will be
implemented, I don't know. Meanwhile, I will take a look at this in due
course (not for some weeks - I'm on vacation for the two weeks after
this) and see if there is an easy temporary fix.

Thanks for the report.

--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book

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