Hi,
I have a question regarding 'old school' type of play where players are responsible for creating map while they explore and also keeping track where they are (in a dungeon, usually) in fear of getting lost. Diminishing resources (food, torches) and all that.

Does this approach work in PBP game and if does what are possible pit falls to avoid?

I have my players do that when they venture into dungeons, but that's relatively rare in my story. But yeah, I like having folks do their own mapping. Feels more authentic, rewarding and dangerous to me.

Also less chance of them asking dumb questions like "Is there anywhere else we haven't explored yet?

I've already told my players that while I will be providing battle maps as needed, overall mapping is up to them, and my game will include a lot of time in dungeons. If they do a bad job of it and get lost, well, sucks to be them. We'll see how that works.

I would say the main thing to beware of is players who expect that their map will look like some perfect map in a printed module. A party map should be abstract - circles for rooms, lines for passageways, notes as needed ("pit trap in center of room", "pull left torch holder to open secret door", "need to come back here with someone who can read Dwarven", etc.) - they shouldn't be spending the time needed to get precise measurements of how big a room is. The map just needs to be enough to keep them from getting lost, and to be able to find their way back to points of interest. It's not supposed to be a cartographic work of art, and they shouldn't expect you to give them the information at the level of detail needed to make it so.

My approach would be pretty much same as yours, Mithgar.

Thank you for your replies. Makes me more confident in planning my game.