Transport Neutral Encapsulation Format (TNEF) is a Microsoft standard for
tunneling rich data over the Internet to a recipient. Rich data includes
Microsoft Rich Text Format (RTF) text, OLE objects, file attachments, and
other application data such as Microsoft Outlook calendar data. Microsoft
Outlook clients and Microsoft Exchange can be configured to format emails
for sending to recipients who use Microsoft Outlook. In such a configuration,
MS Outlook sends the RTF data as plain text and places all other objects
into the TNEF stream, which is usually attached to the email as a file
named winmail.dat. Email systems from other vendors may not be able to
translate winmail.dat. Information on how to prevent winmail data being
sent to Internet users from MS Exchange is documented and publicly available
from the Microsoft Support Web page. However, that configuration may not
be enabled for the MS Exchange systems which send email to your Domino
The TNEF Converter is built into the SMTP task. IBM Lotus Domino uses the
TNEF Converter feature to extract file attachments from the TNEF stream
and include the Rich Text content inside the message. The TNEF Converter
runs on a Domino SMTP server. To enable the TNEF Converter feature, add
TNEFEnableConversion=1 to the NOTES.INI file on the server.
Conversion is disabled by default, which is equivalent to having the TNEFEnableConversion
setting absent or set to 0.
Enable this option so that the fidelity of incoming e-mail sent by Microsoft
Exchange can be improved.
This Domino feature became available in versions 6.5.6 and 7.02. Domino
7.0.2 FP1 and FP2 include fixes to crash issues associated with having
this option enabled. See Technote
TNEFBreakSMIME, TNEFConverter_Log_Level, TNEFAttachRTF, TNEFKeepAttachment
to messages received from the Internet are named as winmail.dat
7.0.2 Release Notes
SMTP task crashes when TNEFEnableConversion=1 is enabled
Domino Configuration Tuner:
This setting is included in the DCT
catalog of best practices.