Vassal is great way to play board style wargames over internet via Pbem.
I took a while to get used to its system but find it very enjoyable now.
Still prefer physical gameplay (I sometimes miss units in Vassal compared to real three dimensional counters) but as needs must.
Thirty Years War game by GMT just started vs Mike Ketterman from USA
Mike is Cathloics and I the 'Prods'
Protestants under Mansfeld put pressure on Elector of Saxony
Paths Of Glory by GMT also versus Mike (we are well into this one now)
Mike is Central Powers (ie the baddies) and Allies under my whims
Shifting Sands by MMP vs Norman Johnston (ex pat Ulsterman in Merry ole England) we are nearing end of the short Sonneblumme scenario in this. Norman is leading the Allies in this one as I try to emulate Herr Rommel and his mates.