Message 687:
From MAILER-DAEMON@localhost6.localdomain6  Sat Feb 19 14:18:05 2011
Return-Path: <MAILER-DAEMON@localhost6.localdomain6>
Date: Sat, 19 Feb 2011 14:18:05 +0200
From: Mail Delivery Subsystem <MAILER-DAEMON@localhost6.localdomain6>
To: postmaster@localhost6.localdomain6
Content-Type: multipart/report; report-type=delivery-status;
	boundary="p1JCI5D1004847.1298117885/localhost6.localdomain6"
Subject: Postmaster notify: see transcript for details
Auto-Submitted: auto-generated (postmaster-notification)
Status: R

Part 1:

The original message was received at Sat, 19 Feb 2011 14:18:05 +0200
from localhost
with id p1JCI5D0004847

   ----- The following addresses had permanent fatal errors -----
Yahav
    (reason: 550 5.1.1 <Yahav@localhost6.localdomain6>... User unknown)
    (expanded from: Yahav)

   ----- Transcript of session follows -----
... while talking to [127.0.0.1]:
>>> DATA
<<< 550 5.1.1 <Yahav@localhost6.localdomain6>... User unknown
550 5.1.1 Yahav... User unknown
<<< 503 5.0.0 Need RCPT (recipient)