Well, and remember: If in doubt, send them an e-mail. You probably want to do that anyways to ensure they have access to that mailbox.
You can try to use a regex as a basic sanity check, so they’ve not accidentally typed a completely different info into there, but the e-mail standard allows so many wild mail addresses, that your basic sanity check might as well be whether they’ve typed an @ into there.
Well, and remember: If in doubt, send them an e-mail. You probably want to do that anyways to ensure they have access to that mailbox.
You can try to use a regex as a basic sanity check, so they’ve not accidentally typed a completely different info into there, but the e-mail standard allows so many wild mail addresses, that your basic sanity check might as well be whether they’ve typed an
@into there.The regexes are written to comply with RFC 5332 and 6854
They are well defined and you can absolutely definitively check whether an address is allowable or not.
https://datatracker.ietf.org/doc/html/rfc5322