Nobody wants to come across as offensive in their business emails. But the very nature of email can get you in trouble. An off-the-context or humorous comment may not be taken jokingly in an email. The smart approach is to draw a line between being too courteous and too friendly. Sarcasm is a big no as well.
4. Failing to use an email greeting.
You shouldn't randomly just start an email. A simple ‘Hi’ or ‘good morning’ is enough to break the ice and keep courtesy intact.