It’s sometimes very difficult to know. Nonetheless, there are some signs that make it very likely that an email is a scam:
– If it came as spam. If we could only advise you of one thing to do to protect yourself from scams, it would be to never respond to spam. 99.999% of all spam are scams.
– If it has misspellings, bad grammar, and/or very poor English.
– If it is a very emotional plea.
– If it asks for a money gram or wire transfer or money order (so you definitely can’t get your money back).
Any of these factors are huge red flags that the email is a scam.