Your mood can easily come through in your written communication as it does in person. The difference between in person and texts or emails is that it is easier to mask – this is a plus, so use it to your advantage. Be mindful of the tone of your email or text.
If you’re angry, finish the draft and let it sit for 24 hours if possible, then review and edit. If you’re in a bitchy mood, feeling snarky – don’t send it, you cannot take it back and worse off to save face you might try to tell the recipient that they are taking the email in the wrong context – that only makes you look bad twice.
Keeping your audience in mind is important – personal, colleague, potential client or acquaintance. Slang, and short form text keeps things light and fun and is all right for personal communication but keep it out of your business emails. Sometimes you develop an ease with a colleague where you have a fun and light way of communicating and that works sometimes but you should try to write in standard English; because after all, it’s business and it will forever be on the company server readily accessible by the powers that be.