Some good mail related links:
+ Letter Writer's Alliance blog
+ Snail Mail Ideas
+ Missive Maven
+ Send Something
+ Swap-bot
+ Postcrossing
+ International Union of Mail Artists
+ Good Mail Day
+ League of Extraordinary Penpals
+ Penpal of the Week
+ Red Letter Day
+ Uncustomary Art's 50 Things To Tell Your Penpal
+ Uncustomary Art's 50 (More0 Things To Tell Your Penpal
+ Envelope Address Hand Lettering Tutorial by Ladyfingers Letterpress
+ Do Not Open Lettering Project
+ The Postal Society