Trolling on CraigsList?

Spoke with my longer-term guy this week; he's been distant and unavailable.
He says things are fine and he's been ill, but there's a guy who sounds an awful lot like him who has some ads on Craigslist.
I did the thing I should not have done tonight and sent a fake email from a fake person.
I KNOW I am probably going to regret taking this step, but I have to know if it is him.
If yes, he's an amazing liar.
If no, major relief.
This way is madness, but I seem to be driving myself there.