When you wake up in the morning, why do you take a shower, wear freshly ironed clothes, fix your hair and put on make-up? You most probably do all these because you care about how you look.
Isn't the same true for writing? If you send a message in all capitals, filled with abbreviations, typos and grammatical errors, what is the reader likely to think of you? He would probably think you couldn't be bothered to take the time to correct the errors.
The idea
If you are attending a meeting or visiting a client, you would make sure you are suitably dressed. Similarly, you must make sure you present yourself appropriately online too. Does your email or report or proposal look good? Have you checked to make sure there are no spelling errors? Is it formatted nicely? Will is make a good impression?
In practice
- Impressions are important, and you can control what they will be. It only takes a little effort to write courteously, to show consideration and common sense. It won't hurt, and the benefits are many.
- Perception is the only reality in written messages. It's you choice whether you want to be perceived as educated and courteous. If you simply don't care, then that will be obvious too.