r3c/Custom-From — pull request #6 by peterdey (2014-01-21 23:49:33+00:00)
Title: Support for pulling email address from arbitrary header

Some MTAs add a header, e.g. X-Original-To, which contains the address that this email was sent to (before forwarding, aliases, etc). This is useful if your setup uses multiple aliases, which all forward to the same mailbox.