Here's my top five. I’m assuming you want to come across as a professional and preserve or build your relationships with your readers.

Keep the To: box blank until you’re ready to send

(Ever hit the send button and gone 'oops!', then had to send a correction?)

Be in professional mode – throughout

Be the voice of calm and reason. Never send an e-mail when you’re grumpy – especially if you’re replying to someone you're convinced really, really deserves a blast from you. Satisfying for a moment, but you won't feel better for long. 'Corrections', 'clarifications' and 'explanations' are in the same category.

Stop, pause, review

We all know that, but it’s just so tempting to hit the send button and tick another one off. A friend of mine intended to write ‘Sorry to hear about your gluten disease’. When he re-read his email at the bottom of the recipient’s reply, the words were ‘Sorry to hear about your gruesome disease’. In that case he was the victim of a dictation programme’s interpretation. Auto-correct and typos can cause the same regrets. Be careful out there.

Send serious emails from your office computer, not your phone

You're much less likely to spot a typo on a phone.

Keep subtle humour out of it

Emails don’t do subtlety well. Humour with people we don’t know, especially from different cultures, is always risky. Subtle humour is even more risky. If you feel that a smiley face might be useful to say 'Hey, just kidding!', revise.