Sam Varshavchik <mrs...@courier-mta.com> wrote:
This is done by Courier. Courier inserts its own Return-Path: header on
locally-delivered mail, that contains the envelope return address.
If the message already has an existing Return-Path: header, it will get
prefixed by the > character.
Out of pure interest, is a header line allowed to begin with a ">" by the RFCs?