Rated 5 out of 5 stars

per wammy el gen. 26, 2022 ·

Works great. I regularly receive .DAT files (text files) and Thunderbird didn't know what to do with them.

This extension opened them up in Notepad, right from the mail interface.

This review is for a previous version of the add-on (0.9.0). 

per kenjiuno (desenvolupador) a mar. 14, 2022 ·

Thanks for using.

By the way, since Thunderbird 91.4.1, you can directly open ".DAT" files or such with correct viewer.

Check TB release notes from:
https://www.thunderbird.net/en-US/thunderbird/91.4.1/releasenotes/

> Temporary files created for forwarded attachments sometimes had the wrong extension