Do not use abbreviations such as (u, b4,ty, ttyl, etc.) in an email. Why? Because it looks tacky. Email is not a text message. Give the person you are writing the respect and time they deserve. Use whole words and nice closings, they will love you for it!
Thank you for the cake. It was delicious! Call me before you leave work. Talk to you soon!
Ty 4 the cake. Yummy! Call me b4 u leave. Ttyl.
Which sounds better to you?