I have a big list of email addresses and I want to find out which of those are duplicates.
How to define "duplicate" is exactly what I'm posting about here.
I know from experience that with Gmail, it's possible to remove all the periods and the mail will go to the same destination. However, from what I've gleaned this is not uniformly true, and some email providers do consider periods part of the unique identifier.
What's your recommendation for how to handle this? I want to err on the side of caution (definitely don't mark an email address as duplicate if it's not). But I don't want to be held back by a tiny edge case either.