Problems appending Stupid Email Disclaimers

For discussion of the issues in general, see the main document on stupid email disclaimers.

Problems appending stupid email disclaimers

Most of the content of this particular document is based on a message posted by David Webb of Much of this is quoted verbatim, although I have made a few changes. It was posted to a mailing list used by email system administrators, and it is used here by permission.

There appear to be 4 ways of applying these disclaimers ranging from the absolutely stupid to the plain silly.

The Absolutely Stupid way
This of course is the way most people appear to be applying these disclaimers.

Have the mailhub apply the disclaimer to the text bodypart of the message.


  1. Many messages don't have any text body parts. eg Someone sends a Word document or an Image.
  2. The first part of the message may not be a text bodypart. Should you add your disclaimer to text bodyparts further in the mail message - The recipient may not bother to read them.

    A subsequent text-bodypart may be a multi-part alternative part in which case it may not be presented to be read.

    Should you add your disclaimer to every text bodypart?

  3. If your mail message passes through your mailhub multiple times (for instance by being forwarded from user to user) should you append the disclaimer multiple times. Can your mail system detect that the disclaimer has already been added? (what performance impact will all this checking have ?)
  4. If the mail message is to automatically processed - such processing could be a simple message to a list server or could be to some other automatic mail handling system - will the handling be able to cope with the appending of your disclaimer.
  5. A future extension of the problem in 4 will be the wide use of XML messages.
  6. Will a PGP signed message still have a valid signature after the mailhub has tampered with the message ?
  7. If your disclaimer is added to a text/html message will the message still display in all html-aware mail clients? Will the disclaimer be displayed?
The Stupid way
Have the mailhub add a new text body-part containing the disclaimer at the start of the message.


  1. Some messages have well defined body-part structures (eg NOTARY messages) which would be destroyed by adding in a new body-part.
  2. Automatic processing of messages would probably be affected again. The receiving system may well just be expecting the message to only have one part and after seeing your disclaimer is not a valid message may discard the whole message without seeing subsequent parts.
  3. Adding a new body-part may be extremely complicated if the message already consisted of a number of multi-part alternative and nested body-parts. If this is not done correctly clients may not be able to read the message correctly
The Fairly Silly way
Individual users put this disclaimer in their own signatures.


  1. Difficult to enforce. Leading to lots of false negatives.
The Merely Silly way
The mailhub puts the disclaimer (or a pointer to a web-page containing the disclaimer) in the message headers. This does not alter the content or structure of the message and would from a mail managers point of view be the best solution.


  1. Most mail clients do not display the headers by default. Hence no one will see the disclaimer.

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