XF 2.0 How to make smilies occur only when the text they replace is totally separate?

[Polaron]

OK so smilies occur when they detect a text they need to replace but this is creating some problems. For example, when someone types in email:pass, they replace the :p in that with the tongue out smilie.

I would like it so that it only replaces text when the text to replace is totally separate like just a :p and not when there is some text before or after it.