Q:

How to stop double-bounce FROM sender in postfix

I am getting huge amount of these in my mail log, and unable to find its originator. What could be the reason? Here is log entry:
postfix/cleanup[9626]: 4413082E40: message-id=<20140220102521.4413082E40@mail.mmnc.co.uk>
postfix/qmgr[9367]: 4413082E40: from=<double-bounce@mail.mmnc.co.uk>, size=255, nrcpt=1 (queue active)

A:

The double-bounce messages are used by postfix for address verification.
You may find more detail here...
http://www.postfix.org/ADDRESS_VERIFICATION_README.html

