[root@sky postfix]# postconf -n
alias_database = $alias_maps
alias_maps = hash:/etc/postfix/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/lib/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
html_directory = no
mail_owner = postfix
mailq_path = /usr/bin/mailq
manpage_directory = /usr/share/man
mydomain = kent.ac.uk
newaliases_path = /usr/bin/newaliases
queue_directory = /var/spool/postfix
readme_directory = no
sample_directory = /etc/postfix/sample
sendmail_path = /usr/sbin/sendmail
setgid_group = postdrop
unknown_local_recipient_reject_code = 550
[root@sky postfix]# hostname
sky


In /etc/postfix/main.cf the following overriden (rest defaults)

mydomain=kent.ac.uk



[andrew@sky ~]$ sendmail ar290@kent.ac.uk
Test this
is a test


^^ this is received from "andrew@kent.ac.uk", not from "andrew@sky.kent.ac.uk"


[andrew@sky ~]$ sendmail -f andrew@sky.kent.ac.uk ar290@kent.ac.uk
More Test


>> Log entry:
un 19 14:48:46 sky postfix/master[4485]: daemon started -- version 2.8.3, configuration /etc/postfix
Jun 19 14:48:52 sky postfix/pickup[4486]: 829B2DABC1: uid=1000 from=<andrew@sky.kent.ac.uk>
Jun 19 14:48:52 sky postfix/cleanup[4490]: 829B2DABC1: message-id=<20110619134852.829B2DABC1@sky.localdomain>
Jun 19 14:48:52 sky postfix/qmgr[4487]: 829B2DABC1: from=<andrew@sky.kent.ac.uk>, size=263, nrcpt=1 (queue active)
Jun 19 14:48:52 sky postfix/smtp[4492]: 829B2DABC1: to=<ar290@kent.ac.uk>, relay=mx6.kent.ac.uk[129.12.21.37]:25, delay=4.2, delays=4.1/0/0.01/0.07, dsn=2.0.0, status=sent (250 OK id=1QYIN3-0003HG-Jk)
Jun 19 14:48:52 sky postfix/qmgr[4487]: 829B2DABC1: removed


Return-path: <andrew@kent.ac.uk>
Envelope-to: ar290@myrtle.ukc.ac.uk
Delivery-date: Sun, 19 Jun 2011 14:49:02 +0100
Received: from hathor.ukc.ac.uk ([129.12.4.12] ident=exim)
	by myrtle.ukc.ac.uk with esmtps (TLSv1:AES256-SHA:256)
	(Exim 4.76)
	(envelope-from <andrew@kent.ac.uk>)
	id 1QYIN4-00030Y-G3
	for ar290@myrtle.ukc.ac.uk; Sun, 19 Jun 2011 14:49:02 +0100
Received: from exim by hathor.ukc.ac.uk with spam-scanned (Exim 4.76)
	(envelope-from <andrew@sky.kent.ac.uk>)
	id 1QYIN3-0004kL-W6
	for ar290@mx.cs.kent.ac.uk; Sun, 19 Jun 2011 14:49:02 +0100
X-UKC-CSSpamCheck-Checker-Version: SpamAssassin 3.2.0 (2007-05-01) on
	hathor.ukc.ac.uk
X-UKC-CSSpamCheck-Level: **
X-UKC-CSSpamCheck-Status: No, score=2.8 required=8.0 tests=AWL,MISSING_HEADERS,
	MISSING_SUBJECT autolearn=no version=3.2.0
Received: from mx6.kent.ac.uk ([129.12.21.37])
	by hathor.ukc.ac.uk with esmtps (TLSv1:AES256-SHA:256)
	(Exim 4.76)
	(envelope-from <andrew@sky.kent.ac.uk>)
	id 1QYIN3-0004kI-SM
	for ar290@mx.cs.kent.ac.uk; Sun, 19 Jun 2011 14:49:01 +0100
Received: from sky.kent.ac.uk ([129.12.41.78] helo=sky.localdomain)
	by mx6.kent.ac.uk with esmtp (Exim 4.72)
	(envelope-from <andrew@sky.kent.ac.uk>)
	id 1QYIN3-0003HG-Jk
	for ar290@kent.ac.uk; Sun, 19 Jun 2011 14:49:01 +0100
Received: by sky.localdomain (Postfix, from userid 1000)
	id 829B2DABC1; Sun, 19 Jun 2011 14:48:52 +0100 (BST)
Message-Id: <20110619134852.829B2DABC1@sky.localdomain>
Date: Sun, 19 Jun 2011 14:48:48 +0100 (BST)
From: andrew@kent.ac.uk


sendmail -f test@sky.kent.ac.uk andrew@sky

Return-Path: <test@sky.kent.ac.uk>
X-Original-To: andrew@sky
Delivered-To: andrew@sky.localdomain
Received: by sky.localdomain (Postfix, from userid 0)
    id AEA6BDABC1; Sun, 19 Jun 2011 15:03:31 +0100 (BST)
Message-Id: <20110619140331.AEA6BDABC1@sky.localdomain>
Date: Sun, 19 Jun 2011 15:03:28 +0100 (BST)
From: test@sky.kent.ac.uk (root)

test this
email