Mailing List Archive

[Bug 2903] New: Rewrite rules in 4.96 cause SMTP connections to drop
https://bugs.exim.org/show_bug.cgi?id=2903

Bug ID: 2903
Summary: Rewrite rules in 4.96 cause SMTP connections to drop
Product: Exim
Version: 4.96
Hardware: x86
OS: Linux
Status: NEW
Severity: bug
Priority: medium
Component: Delivery in general
Assignee: unallocated@exim.org
Reporter: dpc22@cam.ac.uk
CC: exim-dev@exim.org

We upgraded to Exim 4.96 last week.

This morning I received a couple of reports that specific incoming email were
stuck because Exim was dropping connections in the middle of the SMTP
transaction. A bit of trial and error reveals that this happens if (at least)
any of the From:, To: and Reply-To headers in a message have an invalid value
which doesn't include a valid email address.

Unfortunately I didn't pick this up when running the final Exim 4.96 Release
Candidate.

Example cut and pasted from a manual SMTP test:

MAIL FROM:<dpc22@cam.ac.uk>
250 OK
RCPT TO:<dpc22@cam.ac.uk>
250 Accepted
DATA
354 Enter message, ending with "." on a line by itself
From: <dpc22@>

Connection closed by foreign host.

Another example was the following:

From: Sender Name
To: Recipient Name

Repeated subdivisions on my Exim configuration file reveals that the culprit
is:

begin rewrite

*@*.hermes.cam.ac.uk $1@hermes.cam.ac.uk hF

which we no longer need (that service has been shut down). However this works
in 4.95. Things start to work again if I comment out the single rewrite rule.
One of our departments ran into exactly the same issue when they upgraded Exim
a few days before us.

--
You are receiving this mail because:
You are on the CC list for the bug.
--
## List details at https://lists.exim.org/mailman/listinfo/exim-dev Exim details at http://www.exim.org/ ##