Would you pick up on this if you were in a hurry and happen to be expecting a package? (imagine it's in English ๐ ) What immediately catches your eye?
I've seen a US Postal Service spam that would almost fool me. The URL is very close to a real one and when you go to the page (I didn't do it but my coworker did), the page is a very good copy of the real site including the same loading animation and everything.