I like this approach by H.L. Mencken. Though it is not a trait ascribed to many naval officers any longer, answering one's mail was once the standard.

In his correspondence, Mencken adhered to the most basic social principle: reciprocity. If someone wrote to him, he wrote back.   He believed writing back was “only decent politeness.”

He reasoned that if it were he who had initiated correspondence, he would expect the same courtesy. “If I write to a man on any proper business and he fails to answer me at once, I set him down as a boor and an ass.”

Whether the mailman brought 10 or 80 letters, Mencken read and answered them all on the same day. He said, “My mail is so large that if I let it accumulate for even a few days, it would swamp me.”

The postal service used to pick up and deliver mail twice a day. It was frequent enough to allow Mencken to arrange to meet a friend on the same day, but not so frequent as to interrupt his work.

Writing does these three things:

1. Writing improves verbal abilities. 
2. Writing keeps information in our heads.
3. Writing keeps our brains young.