Which is the correct format when saying "Thanks"?

Question

Example: I would like to thank a colleague (Peter) for helping me with a task.
Which is the right way I should type it on my email:

a) Thanks Peter..
b) Thanks, Peter

Answer 1

The correct format would be:

Thank you Peter.

"Thanks" is never a correct format. It is an informal format. In which case you can use it however you want.

Answer 2

b.

You separate the name with a comma when you are addressing someone.

Answer 3

Use the comma in b).