Bug#1146647: exim4: TLS error: The TLS connection was non-properly terminated.

[Timo van Roermund]

Package: exim4
Version: 4.100-1
Severity: normal

Dear Maintainer,

The following error occurs multiple times in the exim logs:

    TLS error on connection from maile-da.linkedin.com [108.174.6.201] (recv): The TLS connection was non-properly terminated.

The reason seems to be that several servers from major service providers (including LinkedIn, Google) intentionally omit close_notify to save a roundtrip, despite it being against the TLS protocol.

It's a known issue, reported long time ago to the exim project. See: https://github.com/Exim/exim/pull/94. And the changelog for the Debian exim4 package suggests that a patch for this issue was cherrypicked in version 4.99-1:

  * Cherrypick patch to avoid logging error on seeing TCP-drop after sending
    QUIT. (https://code.exim.org/exim/exim/issues/3121)

If so, why am I still seeing these errors?

Chers,

Timo

-- System Information:
Debian Release: forky/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'stable-security'), (500, 'stable'), (400, 'unstable'), (300, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 7.1.12+deb14-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages exim4 depends on:
ii  debconf [debconf-2.0]  1.5.92
ii  exim4-base             4.100-1
ii  exim4-daemon-heavy     4.100-1

exim4 recommends no packages.

exim4 suggests no packages.

-- debconf information excluded