Sophos PureMessage SBE: Treatment of TNEF email

  • Article ID: 11640
  • Updated: 27 Oct 2008

In Sophos PureMessage Small Business Edition (SBE) infected TNEF email cannot be disinfected. By default, it is quarantined.

Some PureMessage SBE actions are not available for messages in TNEF, or are different.

  • Delete attachment: TNEF messages are deleted.
  • Delete attachment + quarantine message: TNEF messages are quarantined.
  • Disinfect attachment: the action selected from the 'On failed disinfection' drop-down list is used.
  • Disinfect attachment + quarantine message: the action selected from the 'On failed disinfection' drop-down list is used.

PureMessage SBE does not add subject tags to messages in TNEF.


TNEF is an abbreviation of Transport Neutral Encapsulation Format. It is a format used by Microsoft Exchange and Microsoft Outlook email clients for sending messages in Rich Text Format (RTF).

When Microsoft Exchange sends an RTF message to a Microsoft email client, all formatting information is extracted and encoded in a TNEF block. The message is sent in two parts: a text message with no formatting, and formatting instructions in a TNEF block. Microsoft email clients can process the TNEF block and reformat the message.

Non-Microsoft email clients usually receive the TNEF block as a string of hexadecimal digits within the message, or as an attached file called WINMAIL.DAT. These WINMAIL.DAT files can be safely deleted.

If you need more information or guidance, then please contact technical support.

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