How to Prevent Winmail.dat Attachments From Being Sent in Outlook
If Outlook sends a message using the RTF format for bold text and other text enhancements, it includes the formatting commands in a winmail.dat file. Receiving email clients that do not understand this code display it as an attachment. Outlook may also pack other file attachments in the winmail.dat file. You can get rid of winmail.dat altogether by making sure Outlook does not send mail using RTF. To prevent Outlook from attaching a winmail.dat file when you send an email:
Prevent Winmail.dat Attachments in Outlook 2007 and Outlook 2003
To make sure Outlook 2007 to Outlook 2003 do not attach winmail.dat files:
Disable Winmail.dat for Particular Recipients
The standard settings for outgoing mail formats in Outlook can be overridden for an individual email address. If a recipient still receives a winmail.dat attachment after you have made the settings changes, reset the format for individual addresses.
In Outlook 2019 and 2016
In Outlook 2013, 2010, and 2007
Extract Files from Winmail.dat Without Outlook
If you receive winmail.dat attachments with embedded files, extract them using a winmail.dat decoder on Windows or OS X.
