As I told you, I'm not participating in A Month of Letters. (But I still think it is a good idea. And... wait: I have already sent seven pieces of mail in February!).
I have discovered yesterday a similar initiative: International Correspondence Writing Month (InCoWriMo). This challenge consists in sending a piece of mail every day in February (so 28, not 23 as in A Month of Letters).
Sorry for publishing it today. But it is still 4th, so you can surely catch up in case you are interested. Letters, postcards or notes should be hand-written: "No computers, no typewriters, no emails, no texts, no tweets, no whatever-they-are-on-facebook. InCoWriMo correspondence must be written by hand. Please." (Nothing to do with the fact that a company of pens is sponsoring InCoWriMo).
I am not sure why A Month of Letters is running of February. InCoWriMo chose February because is the shorter month ("We're committed, not crazy"). I would add that maybe is the month with the highest number of raining and cold days (in this part of the world).