formail cache?

formail -rD 8192 file.cache

will extract the name of the sender of mail, and place it into
file.cache, the size of which is limited to 8192 bytes.

My question is, where is this file.cache?  I've tried the above,
and my recipes seem to work, but I want to clear out file.cache,
but I don't see it anywhere....


Jeff Haferman