#######################################################################
### Mail:
#######################################################################
Return-Path: <user@example.com>
Delivered-To: user@example.com
Received: from example.com (localhost [127.0.0.1])
	by mail.example.com (Postfix) with SMTP id 8DCC9F900A
	for <user@example.com>; Fri, 30 Mar 2018 23:31:21 +0300 (MSK)
Subject: test mail
Message-Id: <20180330203129.8DCC9F900A@mail.example.com>
Date: Fri, 30 Mar 2018 23:31:21 +0300 (MSK)
From: user@example.com

Test mail body
.

#######################################################################
### maillog
#######################################################################
Mar 30 23:30:50 mail postfix/postfix-script[2003]: starting the Postfix mail system
Mar 30 23:30:50 mail postfix/master[2005]: daemon started -- version 2.10.1, configuration /etc/postfix
Mar 30 23:31:02 mail postfix/postscreen[2011]: CONNECT from [127.0.0.1]:33460 to [127.0.0.1]:25
Mar 30 23:31:02 mail postfix/postscreen[2011]: WHITELISTED [127.0.0.1]:33460
Mar 30 23:31:02 mail postfix/smtpd[2012]: connect from localhost[127.0.0.1]
Mar 30 23:31:29 mail postfix/smtpd[2012]: 8DCC9F900A: client=localhost[127.0.0.1]
Mar 30 23:31:43 mail postfix/cleanup[2017]: 8DCC9F900A: message-id=<20180330203129.8DCC9F900A@mail.example.com>
Mar 30 23:31:43 mail postfix/qmgr[2007]: 8DCC9F900A: from=<user@example.com>, size=337, nrcpt=1 (queue active)
Mar 30 23:31:43 mail postfix/pipe[2019]: 8DCC9F900A: to=<user@example.com>, relay=dovecot, delay=22, delays=22/0.01/0/0.04, dsn=2.0.0, status=sent (delivered via dovecot service)
Mar 30 23:31:43 mail postfix/qmgr[2007]: 8DCC9F900A: removed
Mar 30 23:32:18 mail postfix/smtpd[2012]: disconnect from localhost[127.0.0.1]

#######################################################################
### CLI send
#######################################################################
[root@mail ~]# nc 127.1 25
220 mail.example.com ESMTP Postfix
helo example.com
250 mail.example.com
mail from: user@example.com
250 2.1.0 Ok
rcpt to: user@example.com
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
Subject: test mail
Test mail body
.
250 2.0.0 Ok: queued as 8DCC9F900A

#######################################################################
### CLI Receive
#######################################################################

[root@mail ~]# nc 127.1 110
+OK Dovecot ready.
user user@example.com
+OK
pass P@ssw0rd
+OK Logged in.
list
+OK 3 messages:
1 1657
2 1391
3 402
.
retr 3
+OK 402 octets
Return-Path: <user@example.com>
Delivered-To: user@example.com
Received: from example.com (localhost [127.0.0.1])
	by mail.example.com (Postfix) with SMTP id 8DCC9F900A
	for <user@example.com>; Fri, 30 Mar 2018 23:31:21 +0300 (MSK)
Subject: test mail
Message-Id: <20180330203129.8DCC9F900A@mail.example.com>
Date: Fri, 30 Mar 2018 23:31:21 +0300 (MSK)
From: user@example.com

Test mail body
.