10 Oct
2014
10 Oct
'14
3:48 p.m.
Srinivas Rao Balla writes:
Oct 10 00:45:54 2014 (8899) All recipients refused: {'it-hyd-owner@intra.domain.com': (550, '5.7.1 Unable to relay')}, msgid: <mailman.0.1412927143.9231.it-hyd@intra.domain.com>
It looks to me like you have an *internal* network configuration issue, such that "intra.domain.com" doesn't recognize the postfix host (also "intra"??) as an authorized local mail originating host. So the message is treated as an unauthorized outsde-to-outside relay and refused.
It appears that you have redacted your host names, so it's hard to make further guesses about what the actual problem is. But it's not Mailman, I think. It's your MTAs or DNS.