Notes about the WDSEML file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The WDSEML file type is primarily associated with 'Thunderbird' by Mozilla Corporation.
Thunderbird is the Mozilla mail client. It comes in multiple languages and versions for multiple operating systems (Windows, OS X, Linux).