Dear Mr. and Ms. President . . .

By CHRISTOPHER JOHN FARLEY

AIDES SAY THE VOLUME OF HILLARY RODHAM CLINTON'S INCOMing mail is "way ahead of anything that's been seen before" by a First Lady. Since Hillary's father took ill last month (he died last Wednesday), her mail has doubled and now stands at about 20,000 letters a week. President Clinton's mail is also heavy -- 1 million pieces in the first six weeks. That's half the amount Bush received in all of 1992.