My office maintains a “three strikes and you’re out” policy on typo’s for cover letters for job applicants. The first- could be spell check, and we overlook it. The second- could be careless proof reading and we are leery but kind. The third- off with his head.
Don’t get me started on typo’s on resumes. We keep a file of the funniest and take it out when someone has a bad day. Some of them are hilarious- unintentionally so, but hilarious.
And grammar? “Let’s eat Grandma” vs. “Let’s eat, grandma!” They are priceless.