What Your Email Etiquette Says About You

Use it.

Here are a few tips on correct usage:

1. Use a colon only after an independent clause for clarification or further explanation.

2. Use a semicolon to connect two closely related independent clauses; do not use it if the clauses could not stand alone as sentences.

3. Use an em dash to show less aggressive continuation -- these are the most flexible punctuation.

If you fail to use punctuation (or fail to use it correctly) you look like an unprofessional pleb.