Let's talk about exclamation marks in professional emails. Is it OK to use an exclamation mark...or two...or three...or 25? Well, it all depends. Here's a good rule of thumb. Don't use an exclamation mark until the other person does first. Some people find exclamation marks unprofessional. Others use the punctuation without thinking twice. But if you let other people make the first move, then you are always in the right. If they have a serious tone, so do you. If they are excited, you are too! Exclamation point. Meet people at their level, and you're always in the clear.