[Dovecot] LDA - Return-Path missing

I seem to have a problem... Deliver relies on Return-Path headers? I tried sending emails from SquirrelMail, and Gmail, and both have caused the same issue (on the recieving end). (I am trying to test this part, the quota exceeded stuff).

deliver(joeblogs): Return-Path missing, rejection reason: Quota exceeded

I can post email headers, and stuff if needed. Does it need the Return-Path header, shouldn't it rely on the From address, if there is no Return-Path?

Tim

Linux Counter user #273956