Hi All,
I have check the original source of mails which i received on my gmail id, their return path are something like :
Example-1 Return-Path: <bounce+c1f9df.93353-subscribername=gmail.com@sub.domain.com>
Example-2 Return-Path: <return-a1422-530063-530081-f26b022c=398315369=8@sub.domain.com>...