The part that matters is in bold. All the email recipient has to do is to click on the link in this bolded section -- it's bolded and underlined in the sample below.

Date: Mon, 5 May 2003 01:05:24 -0700 (PDT)
From: Mail Delivery Subsystem
To: ...
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
        boundary="h4585Oer025474.1052121924"
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)

This is a MIME-encapsulated message

--h4585Oer025474.1052121924

The original message was received at Mon, 5 May 2003 01:05:24 -0700 (PDT)
from apache@localhost

----- The following addresses had permanent fatal errors -----
FakeUser@hizashi.net
(reason: 550 5.0.0 ... (submitted: 18-Jun-03 by outhouse id=105596770176477,hizashi.net) Mail from 212.216.22.67 rejected due to past abuse; (connect) auto-removal: http://vintners.net/outhouse/index.pl?addr=212.216.22.67
(expanded from: FakeUser@hizashi.net)

----- Transcript of session follows -----
... while talking to mail.vintners.net.:
>>> DATA
<<< 550 5.0.0 ... Mail from 212.216.22.67 rejected due to past abuse; (connect) auto-remove: http://vintners.net/outhouse/?addr=212.216.22.67
550 5.1.1 FakeUser@hizashi.net... User unknown
<<< 503 5.0.0 Need RCPT (recipient)

--h4585Oer025474.1052121924/brix.vintners.net
...