Heinlein's automated fan mail response:



Found through Boingboing. ()

I understand that typically he or Ginny would annotate the margins, as appropriate, so it wasn't as impersonal as it may seem. (Remembering this from the bio of Ginny in the Heinlein Journal???)

The reply I received to my one letter to Heinlein circa 1984 has as its entirety the precise text of the last option in that link. However, it is signed by Robert, not Ginny (unless she was forging his signature).

They did ten or more different versions of that form letter starting from the seventies when the mail (particularly from Stranger) became overwhelming (and they were both ill for much of that decade, anyway).