Random send dates
It would be cool to have a random date option. You could click Random Future Date or something and then you could "refine" the randomness, for lack of a better way of stating it. You could say, you know, Random date in a certain year, random day in a certain month, random WEEKDAY in a certain month or a certain year, random WEEKEND in a certain month or a certain year, et cetera. You could even go as far as to be able to highlight a specific week to pick a random send date for. That would make it more of a surprise, especially if someone wants to send a letter not too far into the future but still wants to be surprised about what day they will be receiving it. I apologize for my atrocious grammar, but I am too exhausted to worry about fixing it right now. I promise, I do know how to properly write!