Here are some commonly used email abbreviations  for those of you who are short on time:-

J/K - Just Kidding
LMAO - Laughing my a.. off
*S* - Smile
@-->-->-- A flower
ROFLMAO - Rolling on the floor laughing my a.. off
BRB - be right back
BBL - be back later
BTW -   By The Way
FYI -& nbsp;  For Your Information
IMHO -  In My Humble/Honest Opinion
RTFM -  Read The Manual
LOL -   Laughing Out Loud
RSN -   Real Soon Now
ROTFL - Rolling On The Floor Laughing
TTYL -  Talk To You Later
TIA -   Thanks In Advance
<g> -   grin
If words can't express what you are feeling,try these commonly used symbolic 
gestures to express yourself:-
:-)   Basic smiley,used with a sarcastic or joking statement since we can't hear voice inflection over e-mail.
;-)   Winky smiley. User just made a flirtatious and/or sarcastic remark. More of a "don't hit me for what I just said" smiley.
:-(   Frowning smiley. User did not like that last statement or is upset or depressed about something.
:-I   Indifferent smiley, better than a :-( but not quite as good as a :-).
:->   User just made a really biting sarcastic remark, worse than a ;-).