Please use a personal email. My email is ‘mail’ @ ‘my actual name’. It does not get more personal than that
But you can’t use emails starting with mail@, admin@, support@, info@, main@, etc.
Instead they advised me (3 times) to create a personal email on a service like Yahoo, Outlook, Gmail, Orange, etc
If they know this case. In other email services dots are usually not a junk characters.
For the same of checking uniqueness it’s probably fine to just ignore them. Yeah, it sucks if johndoe@obscure.domain and john.doe@obscure.domain can’t sign the same petition but outside of the big email services I imagine that kind of collision is pretty rare