Undelivered Mail Returned to Sender

[MAILER-DAEMON@xxxxxxxxxxxxxxx (Mail Delivery System)]

This is the Proprietary program at host zixvpm.bgfh.com.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                        The Proprietary program

<mayfield@xxxxxxxx>: host 192.168.114.11[192.168.114.11] said: 550 Rule imposed
    mailbox access for mayfield@xxxxxxxx refused (in reply to RCPT TO command)

Reporting-MTA: dns; zixvpm.bgfh.com
X-Proprietary-Queue-ID: 89A1B88C0E6
X-Proprietary-Sender: rfc822; kernprof@oss.sgi.com
Arrival-Date: Sun, 20 Apr 2008 02:09:17 -0400 (EDT)

Final-Recipient: rfc822; mayfield@bgfh.com
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Proprietary; host 192.168.114.11[192.168.114.11] said: 550
    Rule imposed mailbox access for mayfield@bgfh.com refused (in reply to RCPT
    TO command)
> --- Begin Message ---
>
> --- End Message ---