Re: timeout after DATA Error

From: dogbert (no email)
Date: Thu Dec 01 2005 - 11:12:04 EST

  • Next message: Chris St. Pierre: "Re: Another SPAM doubt"

    Wietse Venema wrote:
    > Wietse:
    >>> To diagnose the problem you will need to record a failed session
    >>> with, for example tcpdump. Record the full packet content:
    >>>
    >>> tcpdump -s 2000 -i interface -w /file/name
    >>>
    >>> There has been a recent flurry of "timeout after DATA" problems
    >>> with MS Exchange 5 because it was sending mail that did not end in
    >>> "<CR><LF>.<CR><LF>".
    >
    > dogbert:
    >> I've analyzed some sessions with Ethereal and found that the main difference
    >> between a working mail (that pass through postifx) and a bad message (that
    >> stuck) is that the latter doesn't terminate with a \r\n.\r\n but with a packet
    >> of EOM (if I decode with ethereal the full SMTP transmission it contain the last
    >> . for ending the session but it is not present in the MESSAGE BODY part of the
    >> session).
    >
    > What is EOM?
    >
    > Can I see the data that is actually sent? I hate it when helpful
    > software changes the evidence.
    >
    > If the mail does not end in "<CR><LF>.<CR><LF>" then it does
    > not comply with the SMTP protocol, and all bets are off.
    >
    > Wietse
    >

    I believe that EOM stand for End Of Message and I hope that if Ethereal can
    understand is as part of an SMTP transaction it somehow comply with smtp standard.

    Here is what Ethereal decode of the transaction:
    ------------------------------------------------
    220 mailfilter.testdomain.it

    EHLO mail1.testdomain.it

    250-mailfilter.testdomain.it
    250-SIZE 1000000000
    250-VRFY
    250-ETRN
    250 8BITMIME

    MAIL FROM: <> SIZE=757

    250 Ok

    RCPT TO: <>

    250 Ok

    DATA

    354 End data with <CR><LF>.<CR><LF>

    X-SEF-Processed: 5_0_0_713__2005_12_01_17_01_52
    X-SEF-AE0723B2-1DB9-4A10-B06E-C6DC66A014F9: 1
    Received: from Unknown [172.28.253.1] by mail1.testdomain.it - SurfControl
    E-mail Filter (5.0); gio, 01 dic 2005 17:01:52 +0100
    Message-ID: <438F1E70 dot 1060608 at tiscali dot it>
    Date: Thu, 01 Dec 2005 17:01:52 +0100
    From: dogbert <>
    User-Agent: Thunderbird 1.5 (Windows/20051025)
    MIME-Version: 1.0
    To:
    Subject: test message
    Content-Type: text/plain; charset=ISO-8859-1; format=flowed
    Content-Transfer-Encoding: 7bit

    this is a test message.

    .

    ------------------------------------------------
    the last dot is the <CR><LF>.<CR><LF> but I'm going to make a tcpdump of the
    session if you prefer it as it is (without decoding).


  • Next message: Chris St. Pierre: "Re: Another SPAM doubt"





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