Differences between revisions 16 and 17
Revision 16 as of 2024-06-05 11:42:49
Size: 1591
Editor: vbarmettler
Comment:
Revision 17 as of 2024-08-19 13:59:07
Size: 1589
Editor: vbarmettler
Comment:
Deletions are marked like this. Additions are marked like this.
Line 25: Line 25:
 * Click on '''Trust Center''' in the right menu.  * Click on '''Trust Center''' in the left menu.
Line 33: Line 33:
 * In the Trust Center, select '''Email Security''' from the right menu.  * In the Trust Center, select '''Email Security''' from the left menu.

Outlook: How to stop sending winmail.dat attachments

Problem

When sending an email signed with an S/MIME certificate, it can arrive with a winmail.dat attachment on non-Outlook clients. This file includes the email, the S/MIME signature, and any other attachments, making it cumbersome for recipients like support@isg.ee.ethz.ch to extract the contents. To prevent this, you can enable the "Send clear text signed message when sending signed messages" setting in Classic Outlook.

Solution

This setting must be enabled before creating an email, as it is not applied to the current email being edited.

1. Open Options Window

  • Go to the File menu in the top-left corner of the main page.

winmail_dat_file_menu.png

  • Click on Options at the bottom-left corner.

winmail_dat_options.png

2. Access Trust Center Settings

  • Click on Trust Center in the left menu.

  • Open it by clicking the Trust Center Settings button.

winmail_dat_trust_center.png

3. Enable Clear Text Signed Messages

  • In the Trust Center, select Email Security from the left menu.

  • Enable Send clear text signed message when sending signed messages to avoid sending winmail.dat attachments.

winmail_dat_clear.png

By following these steps, you can ensure your emails arrive without the winmail.dat attachment, making it easier for recipients to access your email and attachments.


CategoryWNSU

FAQ/winmail_dat (last edited 2024-08-19 13:59:07 by vbarmettler)