The ones that jump out at me are misspelled words and awkward phrasing. As a writer I’m very alert to bad use of language.
“Congratulations!” is also a big red flag.
A very big one is correctly written excellently impersonated bank or credit card notices but one giveaway there is not addressing you by name and/or asking for social security numbers or passwords in the email.
Contributor: Ben Bryant from entertainment books by ben and ben bryant video