A. You try to select relevant information.
B. You include as much information as possible.

A. Sentences are shortened.
B. Sentences should be complete as in personal letters.

A. Full stops must be used instead of commas.
B. Capital letters, underlined words and exclamation marks are often used to give emphasis.

A. Insert a few questions to motivate an answer from the other person.
B. Talk about yourself, mostly.