[fetchmail] Patch that sets MAIL FROM: to a constant address

Hi!

My ISP's mailer deamon does not set Return-Path:, so in most cases
Fetchmail gets sender's address from the From: header that varies
from totally bogus to syntactically incorrect.

With the attached patch one can set a constant MAIL FROM: address.
Works for me.

Nagy Ferenc László, waiting for comments

smtpmailfrom-patch.gz
Description: application/gunzip