X-MS-TNEF-Correlator mail header

Question : X-MS-TNEF-Correlator mail header


Can anyone provide information on the mail header


All I can find is examples of its use within headers rather than its reason for existance. I am assuming it references the msg-id field, that is all I have to go on.



Solution: X-MS-TNEF-Correlator mail header

Pronounced tee-neff, and short for Transport Neutral Encapsulation Format, a proprietary format used by the Microsoft Exchange and Outlook e-mail clients when sending messages formatted as Rich Text Format (RTF). When Microsoft Exchange thinks that it is sending a message to another Microsoft e-mail client, it extracts all the formatting information and encodes it in a special TNEF block. It then sends the message in two parts – the text message with the formatting removed and the formatting instructions in the TNEF block. On the receiving side, a Microsoft e-mail client processes the TNEF block and re-formats the message.

Unfortunately, most non-Microsoft e-mail clients cannot decipher TNEF blocks. Consequently, when you receive a TNEF-encoded message with a non-Microsoft e-mail client, the TNEF part appears as a long sequence of hexadecimal digits, either in the message itself or as an attached file (usually named WINMAIL.DAT). These WINMAIL.DAT files serve no useful purpose so you can delete them.