Of the information shared via email, it is possible that much of it could be very confidential. This writer approaches the issue of confidentiality in the concept of a 'sealed' envelop, using a zipped folder containing a message of some sort, as opposed to using the originating application's mechanism to 'protect' its contents. This has advantages:
Of the many zip applications, this writer finds the freely available application by 7-zip.org to be a most suitable, versatile and convenient in the PC-Win environment.
First, download 7-zip and install it. After the instal, it is recommended to restart the computer.
Secondly, open the Explorer and choose the target file or files of the same directory (pressing simultaneously the 'Ctl' button) thus high-lighting it (or them).
Thirdly and while the cursor is on one of the highlighted files, right-click on the mouse - the 7zip menu should appear on the menu list (if not there, open 7-Zip with "Administrative Rights"and go to "Tool"->"Options"->"7-zip" where one turns on the two "integrate to context menu" choices).
Lastly, select 'Add to archive' and tick on "encrypt file names" , enter a 8-9 character password and click 'OK'. The zipped folder should then appear in the same directory as the chosen files.
First the recipient needs to have 7-zip functional on his/her PC. If in doubt, one can easily send the recipient a instruction page, such as, Howto Install 7zip
With 7-zip software installed, clicking on the 7zip file will automatically bring up the 7-zip application whereby the file(s) therein can be 'extracted' in the directory where the zipped folder is found or to another folder, if so directed.