Questions on Snail Mail? What are they?

What are the questions and issues on Snail Mail people have? I can think of a few which I'll list below, but what other questions arise for this hobby?

• How do you keep track of correspondence?
• How do you store your letters?
• What do you write in letters?
• Why do you write letters in a digital age?
• What are some of the things I can enclose with the letter?
• Does age and gender matter when seeking out new penpals?
• What do I do with the used stamps if I am not keeping the envelopes?
• Do people still write with fountain pens?

Feel free to comment and answer any of these questions.