Basically, its more of communication style and nobody has the reason to say one is better than other. Its more of personal choice. For example, many times, managers say that phone call is LIVE and just call the person and resolve the issue. On the other hand, the same person doesnt realize that when I call somebody, I am putting higher importance to my issue and disturbing somebody from his regular work. I also dont give him any time to think about my issue or getting complete picture. Worst thing is - it loses many points to be covered as people forget about number of points to discuss unless you already have a summary in hand. I would always prefer to first have a small summary and issue note prepared with the points to be covered, sent to concerned persons in advance, ask for their convenient time for call and then only go for a call.
NEVER EVER TYPE THE ADDRESSEE NAME AND THEN COMMENCE TO WRITE THE EMAIL. ALSO NEVER USE THE REPLY OPTION WHEN YOU ARE IN OFF MOOD! ONE MISTAKE OF PRESSING THE RETURN BUTTON CAN BE CURTAINS!
though it is a fact that secrecy is not maintained in e-mail messages but quick action is taken by the person to whom it is sent which is not possible even when the letter is sent by speed post.but never share your secrets which may harm you at a later date.avoid messaging indent or abusive language which may hurt others.