Disable Mail-Forwarding for Lotus Notes programmatically

Lotus Notes has a nifty feature to lull managers into false safety: for volatile/unsafe e-mails (or users), it let’s you disable printing/forwarding and copying to clipboard. This can be done using rules, on the SMTP server and on a per e-mail basis. When writing somebody you really don’t trust with some information (but in his inability to spread the word otherwise – by copy/pasting for example), writing a mail would look like this:


Now, if your victim wants to forward your mail, Lotus Notes would respond with a little pop-up:


This certainly looks like a magical and proprietary feature, doesn’t it?  Let’s look at the source of such a “mail”(aka memo in Notus’ language) – you will have to forward it to another mail-client though, because memos can’t be displayed in source:

Subject: Testnachricht
MIME-Version: 1.0
Sensitivity: Private
X-Mailer: Lotus Notes Release 6.5.5  CCH1 March 07, 2006

As you can see, there is a proprietary meta-flag Sensitivity: Private. It can be reproduced with any decent mail user agent or programmatically. What follows is a little Python code snippet that just does the trick:

import smtplib
from email.message import Message
msg = Message()
msg.set_payload("Testmessage Body")
msg["Subject"] = "Testmessage from Python"
msg["From"] = "preek@dispatched.ch"
msg["To"] = "somebody@somewhere.com"
msg["Sensitivity"] = "Private"
smtp = smtplib.SMTP("localhost")
smtp.sendmail("preek@dispatched.ch", "somebody@somewhere.com", msg.as_string())

But please, don’t use this information unless you absolutely have to. Lotus Notes.. *brr*.


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Category: articles | Tags: , , , , , , , , , , 5 comments »

5 Responses to “Disable Mail-Forwarding for Lotus Notes programmatically”

  1. rosostrov.ru

    Best article, lots of intersting things to digest. Very informative

  2. Mike

    You somehow think this functionality is unique to Notes?

    The only thing clear in this posting is that you really don’t know what you’re talking about.

    From RFC 2156:

    “Sensitivity Indication
    Supported as new RFC 822 header (Sensitivity:).”

    RFC 4021:

    2.1.55. Header Field: Sensitivity

    Message content sensitivity

    Applicable protocol: Mail [18]

    Status: standards-track

    Author/change controller:
    IETF (mailto:iesg@ietf.org)
    Internet Engineering Task Force

    Specification document(s):
    RFC 2156 [10]

    Related information:
    How sensitive it is to disclose this message to people other than
    the specified recipients. Values: Personal, private, and company
    confidential. The absence of this header field in messages
    gatewayed from X.400 indicates that the message is not sensitive.
    Proposed for use with RFC 2156 (MIXER) [10] and RFC 3801 (VPIM)

  3. Alain M. Lafon

    I never said it is unique to Lotus Notes.

    Anyway, it’s the only MUA I’ve seen that actively uses this feature.

    Apart from that, thank you for your constructive input.

  4. Alain M. Lafon


  5. Mark

    good article. Points you in the right direction by excluding another Lotus Notes Magic.

    responding like “Mike” reminds me a lot more to people that don’t know what they talk about.
    okay, you can qoute some RFCs….great,Congratulations!