This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Mozilla Support में खोजें

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

cant open attachments of ppt and excel

  • 4 प्रत्युत्तर
  • 1 यह समस्या है
  • 1 view
  • के द्वारा अंतिम प्रतियुतर sfhowes

more options

I had updated my Thunderbird to 60.3.2 few weeks ago and ever since I cant open attachments of excel and powerpoint sent via email. The pptx and attachments are getting converted to winmail.dat or office xml handler and not opening.

When I open the same emails in webmail I can open these attachments.


Can you please advise how to resolve

I had updated my Thunderbird to 60.3.2 few weeks ago and ever since I cant open attachments of excel and powerpoint sent via email. The pptx and attachments are getting converted to winmail.dat or office xml handler and not opening. When I open the same emails in webmail I can open these attachments. Can you please advise how to resolve

All Replies (4)

more options

When folk send emails from outlook it tried to use the proprietary Microsoft TNEF format. Thunderbird does not have a license to use TNEF. So just contact your senders and ask them to send real email not Microsoft proprietary stuff.

https://support.mozilla.org/en-US/kb/what-winmaildat-attachment

The article talks about an add-on and links to it, but it has not been updated to support Thunderbird versions after 12. So I guess the author has abandoned it.

more options

Hi Matt the same people have been using the same software even earlier and now. These are people with who I have daily email interaction. While thunderbird responded earlier and all attached files could be opened but not after their last update.

more options

You mention winmail.dat. That tells you everything about the problem. The sender maybe using the same Outlook program, but they or an update has changed some settings in Outlook so that it is not sending emails in a compatible format. They are only sending emails in a format that other Outlook users can use. They need to change those settings as advised by Microsoft. see link at bottom of page.

The Microsoft Outlook e-mail program sometimes sends e-mails in the Transport Neutral Encapsulation Format (TNEF). Most other e-mail programs, including Thunderbird, do not understand TNEF.

If your e-mail program doesn't understand TNEF, instead of seeing the e-mail and/or attachment, you may only see an attachment named "winmail.dat" or "Part 1.2" that you cannot open. Also, sometimes you may receive a TNEF attachment with a generic name such as ATT00008.dat or ATT00005.eml instead.

The sender can avoid sending TNEF attachments by by turning off TNEF in Outlook. When Outlook is configured to send e-mail in "Outlook Rich Text Format", it may use TNEF. When it sends in "HTML" or "Plain Text", it uses standard, compatible formats.