Victor Raymond's online Play-by-Post game is in the process of restarting here -
(Insert gratuitous self plug!)
My own Play-by-Post campaign is due to restart within a week over here-
-My offering utilizes a Tekumel conversion of the D6 Fantasy rules. (D6 Fantasy is now a FREE open source rule-set, found here in online srd format) My conversion notes can be found here.
-I believe Victor is running the original EPT whitebox.
-My game has room for '1' additional player.
-You will have to contact Victor on behalf of his game to determine if there are openings still in his campaign.
If you are aware of any ADDITIONAL play-by-post games that are actively 'in play', reply with a link please by adding a comment to this posting.