From my professional experience, I learnt a few hints and tips about email writing for business purposes that I would like to share.
We all have the tendency to write the same way we speak. Writing is different!
When you write, especially an email, you have to be very clear, short and to the point.
1- People tend to resist reading very long emails, even if they are important. So you need to write short emails.
2- Written words are harsher than spoken ones. The same thing that you can say to someone, if written can annoy or hurt him although it did not when orally said. This is because when you speak it out, the way you say it makes a difference. So take care, when you write an email, revise it several times to make sure that the tone of it is not harsh and will not annoy your reader.
3- After you write your email, proof read it for rephrasing. It is important to make sure that all sentences can not have more than one meaning. If you write sentences that can be interpreted in different ways, you will loose the aim of your email. You can even cause problems or delayed deliveries.
4- Never use colors, special signs (like exclamation mark), Capital letters or bold fonts to express your anger or to emphasize something. It gives the impression that you are fighting. Even if you have the right to be angry, do not show it this way because you will definitely lose your audience.
5- Never use abbreviations unless you mention the full phrase first and its abbreviation beside it in brackets. Then in the rest of the email body you can use the abbreviation. (Unless of course it is a well known abbreviation in your business or something that is frequently used and you are sure it is known to the recipient)
6- After you write your email, proof read it again for spelling mistakes. A business email with spelling mistakes is repulsive.
7-After you write your email, proof read it a third time for grammatical and logical mistakes. A business email with such mistakes is extremely repulsive.
8- Do not CC: someone on an email unless absolutely necessary, requested by a manager or the CCd: person will do something related to the email (has a role).
9- The color of your font should not be red, green, yellow or blue. Use colors that are comfortable for the eye and would not cause your recipient to refrain from reading your email.