What's the best way to contact an inmate you want to write to?

[patsyrant]

Hi, it's patsyrant here again with another question with which to bother you kind folks.
I found the inmate I wanted to become pen pals with, and made my initial contact via the message system on the website (prison inmates online). That message system, whereby you send him a message introducing yourself that adds both your snail mail and email addresses in case they have corrlinks etc, only allows you 500 characters. I find it difficult to say anything the short way, so really struggled with this, and wasn't at all sure that I'd given a true- and deliriously fascinating, of course- depiction of myself in that message. But it seemed by far the quickest way to introduce myself to him and begin correspondence, especially given that I'm writing from across the pond.
This was about 3 weeks ago, and I haven't heard from him. He's a federal inmate and does have corrlinks so I presumed that he'd have used that rather than snail mail. Now I'm by no means certain that he WOULD have written back to me. I know lots of these guys can have a fairly long list of pen pals and so he may have thought "meh, who needs ANOTHER guy to write to? I'm getting RSI from all my correspondence as it is.."
So my question is (told you I can't say anything the short way), is it best NOT to use these intro messages and go ahead writing a longer letter myself? I'm not going to write to the same guy again (that would seem too much like stalking to me, and stalking someone in prison would be bad for my self esteem), but I'd appreciate a tip or two in opening lines of communication with other inmates.