How to open the attachment called “winmail.dat”.

Users.

The attachment called “winmail.dat” is the special format called “TNEF-encoded messages” for Microsoft Outlook (E-mail software). Basically, this file cannot open except Microsoft Outlook.

• Information: http://kb.mozillazine.org/Winmail.dat_attachments

There are the following two correspondences

1. (Best) Change E-mail setting of sender.
2. Use of special software for opening “winmail.dat”.

In case of no.1, please see “Disable TNEF-encoded messages at Microsoft Outlook”.

Disable “TNEF-encoded messages” at Microsoft Outlook.

• Outlook 2003
   In “HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Options\Mail”, 
    The value of DontEncodeCustomNote changes to 1. (If there is not the value, please create it.)
• Outlook 2007
     In “HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Options\Mail”, 
    The value of DontEncodeCustomNote changes to 1. (If there is not the value, please create it.)

In case of Microsoft Outlook XP, I think that you may replace 11.0 to 10.0. However, to directly change the registration information is high risk because the OS may crash if you misstalk a setting. Therefore, I developed the  following tools.

• [download id=43 format=7]
  • Disable-winmail-Outlook2003.reg:  Disable “TNEF-encoded messages” (Use standard format) for Outlook2003.
  • Disable-winmail-Outlook2007.reg:  Disable “TNEF-encoded messages” (Use standard format) for Outlook2007.
  • Enable-winmail-Outlook2003.reg:  Restore to Default setting (Use “TNEF-encoded messages” format for Outlook2003)
  • Enable-winmail-Outlook2007.reg:  Restore to Default setting (Use “TNEF-encoded messages” format for Outlook2007)

How to open winmail.dat in your PC without using Microsoft Outlook

Pleasee refer  “Winmail Opener” page.