Selling house w/out any agents, HOW to verify out of state offer?

[Jason V.]

I just listed my house for sale on Zillow / Trulia *only* yesterday and received an informal offer that we're both happy with.  Neither of us have an agent, but this buyer seems like he's done this before (buying out of state properties with cash, "fast closing", etc.).

I asked how he intends to submit his offer, and he says he's going to get with his closing company and email it to me.  I had 2 types of buyers in mind I was expecting -- local buyer w/out agent, which I would recommend we go to a local closing company of common ground.... or a local buyer with agent, in which case the agent would smooth some things out and we'd *still* be using a local closing company.

What I wasn't expecting was an out of state buyer using an out of state closing company....  Can someone share things I'll need to expect or things to watch out for??   I'm pretty sure he's legit, as I see online postings with his phone number, stating that he will give fair cash offers for houses with quick closing, etc.... but I definitely need to know what to expect.  Any tips or suggestions??