Ah, agents,.,..
I periodically get unsolicited emails trying to buy one or another of my domains. The only one I have so far sold, which was for a domain I wasn't actually using, I checked the IP that the innocent looking webmail email came from, and discovered it was from one of the large registrars.. With that knowledge, I negotiated them up to about 20 times the initial otherwise-reasonable-sounding offer, about the same as four months salary! Not bad for a domain I originally got from freenetname.co.uk. (anybody remember them?) I might have held out for more (it ended up as a subsidiary website to one of the leading magazines in it's field!) but I was happy enough with it,