E-mail has become such a mainstream way of communication that too many people use it without keeping email etiquettes in mind. There are some unique idiosyncrasies that you need to keep in mind when typing an e-mail. These include:-
Do not type in ALL CAPS. People construe that as you're shouting at them - definitely not polite behaviour.
Do not type all lowercase, either. This is too casual, especially if you're sending a business e-mail.
Avoid using emotions in a business e-mail. Again, too casual.
Do not neglect to address someone as Mr or Ms, the first time you contact him or her by e-mail.
Keep good spelling and grammar in mind when typing.
Like any document you write on your computer, you should always proofread, spell check and make sure your grammar is up to the mark before sending an e-mail.
If you don't have the time to run a spell check, then you really don't have the time to be sending an e-mail.
If you know that your employer frowns on the personal use of e-mail at work don't do it.
If personal e-mails are allowed at work, don't overwhelm your colleagues with forwards of jokes, etc. You're at your job to work, not to share funny messages.
There are many sites that you'd be wise to stay away from, especially if you're web browsing with children or you're at work.
You shouldn't share friend's or family member's information with any web sites without asking them first.
You need to think each time your cell phone rings whether it is truly a convenient or considerate time to answer.
You should never answer a cell phone that rings in the middle of a dinner or a business meeting.
There is nothing wrong in taking calls in public. In fact, being outside may be the ideal place to talk on your cell phone because you won't be bothering those in close to you.
There are some places where you might want to think twice about talking on your cell phone e.g. in any store, restaurant, doctor's dispensary, classroom or service establishment, at a sporting event, in the queue at the bank, movie ticket counter or anywhere else where others are nearby, or at a cultural event, including plays, museums or movie theatre.
If you're going to get into anything personal or emotional, you would be best to find a private place to have that conversation.