How to use search-replace and regular expressions in Notepad++ to remove all duplicate e-mail addresses in a string?

Question

Notepad++

There are lines
site.com: [email protected],[email protected],mail.site.com
nite.com: [email protected],[email protected],[email protected]
After search-replace should remain :
site.com: [email protected],[email protected]
nite.com: [email protected],[email protected]

Answer 1

I play, but I still don't understand what I'm doing. This helped, like
(\b(\[email protected]*.com)\b.*)\2\b
https://regex101.com/r/QNmgpu/4