1. Use proper Grammar while writing professional letters because you don't want to look unintelligible
2. Don't Use long sentences in Emails or information because people don't want to read long paragraphs.
3.Don't Spam people find that annoying and it might cause them to report you or block you from the server or website
4. Don't send Chain Letters or Hoaxes people might also find it annoying and people will report you or cause a problem.
5. Don't Write in All Caps Because It's Yelling in writing or text and people find it rude.
6. Don't use negative language or racist language because you can get fined or charged and end up in jail.
7. Don't send unnecessary conversation or attachments on Emails it may carry a virus.
8. Put liabilities on your Emails so you won't get sued for any viruses because if something happens like a virus you might get sued.
9. Don't send large Attachments on Emails because large attachments might freeze up the persons computer.
10. Don't post or send Jokes people will find it irritating and annoying and you might get reported.