Re: Encryption between mail servers

From: Matthias Leisi (no email)
Date: Thu Mar 01 2007 - 03:54:55 EST

  • Next message: Jan P. Kessler: "Re: smtpd_restriction_classes Question"

    > On Wed, Feb 28, 2007 at 01:15:28PM -1000, Ren? van den Berg wrote:
    >
    >> Can anybody provide me with a percentage of email that is sent
    >> encrypted between mail servers.
    >
    > Which mail servers?

    I did a survey of about 1'000 domains from my log last year (details at
    [1], in german). Similar to a survey from the University of applied
    sciences in Zurich in 2004 [2] (for actvie .ch and .li domains), I found
    about 30% of the mailservers offer TLS -- for various values of "offering"
    (certificates from home-grown or "well-known" CAs, CN [not] matching the
    MX name etc).

    More interesting than the number/ratio of mailservers would be the ratio
    of mail volume (after spamfiltering for incoming messages, or generally
    for outgoing), and this will highly depend on the usage pattern (eg retail
    vs. business-to-business communication).

    What such surveys are obviously not able to find out is to what degree the
    use of TLS encryption and certificate verification is enforced by the
    remote end (eg, will it let mail to example.com pass through even if the
    certificate verification failed).

    -- Matthias

    [1] http://matthias.leisi.net/archives/156-TLS-Nutzung-Wer,-Wo,-Was.html
    [2] Used to be at http://security.zhwin.ch/infoweek.pdf but this seems to
    be gone; referenced in
    http://matthias.leisi.net/archives/162-Mehr-TLS-Statistik.html (also in
    german)


  • Next message: Jan P. Kessler: "Re: smtpd_restriction_classes Question"





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