TNEF Conversion Candidates

Items that need to be converted to TNEF in a backboned message are those items that cannot be easily mapped into foreign system attributes. If the foreign system supports the same functionality as Microsoft Exchange Server, the gateway should include message attributes in the native foreign message rather than encapsulate them. Items that may need to be encapsulated include the following:

• Per-recipient attributes Put any per-recipient attributes the foreign system does not support into a TNEF-encoded recipient table.
• Attachments If the foreign system supports attachments, it is best to convert these to native foreign system attachments and then rebuild the message. Then the attachments can be read directly if the message goes to a native client. If the foreign system does not support attachments, your gateway will need to encode them at the end of the message body. This is often necessary when backboning over a SMTP-based system, in which case attachments should be encoded using the standard Unix uuencode format.
• OLE objects Encapsulate these because most foreign systems do not support OLE.
• Rich text This should be encapsulated.