HELO mail.external.tld
MAIL FROM: user@external.tld
RCPT TO: user1@localhost.localdomain
DATA
From: Docker Mail Server <dockermailserver@external.tld>
To: Existing Local User <user1@localhost.localdomain>
Date: Sat, 22 May 2010 07:43:25 -0400
Subject: Test Message
This is a test mail.

.
QUIT