LOL...or no?

This isn't really an illness related post. It's more a "I'm new to this whole grown up thing" post.

So, I know how to be formal and professional. Unlike many of the youngans today, I know how to send a proper email/letter with commas, capitalization and periods. Yea me.

When I write friends tho, (example) I enjoy the new abandon of all of the grammar formalities listed above. i write like this lol

So, here's the thing. Writing emails (as with writing letters...but they are fast letters) has drawbacks. The biggee is that they have the possibility of being misinterpreted. My tone might be simple and include straightforward questions but it could be read as rude or impatient. This is partly why the :) has become so popular. You know I'm writing a joke when the sentence is followed by a :)

So, I have more and more emails every day with people I barely know but really like. People who are booking me for things or helping me make important contacts. I use :) pretty quickly, like maybe 4th or 5th email into a conversation with a new person. I am finding myself really wanting to use LOL now.

Is it ever appropriate to use LOL in a professional email? If yes, in what circumstances? If no, what about :) ? Is that innapropriate?

Our world is changing. The younger generation doesn't even know what a cover letter is and people older than me don't know what btw means. I feel stuck in the middle of a transforming email culture.

Any protocols or are we left to our own ediquette devices now??