Extract emails from files contained in various folders with grep and sort them

Question

I am trying to extract all email address from a specific TLD from files that are located in a big folder and in some sub-folders (maybe this is the issue? nb. I am in the correct directory where the folders and files are).

I am trying to find a way to sort and remove duplicate from the result of the grep command

I have got the following command in Cygwin:

grep -E -o -h -r '\b[A-Za-z0-9._%+-][e-mail]' * | sort -u > output.txt

When I am trying to test it with some files and folders I created, it works fine, but when I am putting it to the test with the real data I want to extract the emails, the output.txt is created, but there are no emails in it, and I have absolutely no idea why the line of command remains active with