Paging Level3 Mail Admins: Your messagelabs config is broken

[danm at prime.gushi.org (Dan Mahoney, System Admin)]

Note: sending this from my personal account to increase odds of someone 
seeing it.  My work address is dmahoney at isc.org.

ISC is having trouble mailing noc at level3.net, we keep getting redirected 
to a messagelabs error, seems to be happening from any address we send 
from, including personal addresses and the (sender/envelope) address of 
our ticket system.

This is probably nonoptimal.

You can reach me voice at 650-423-1362, or our noc number at 650-423-1310.

Final-Recipient: rfc822; noc at Level3.net
Original-Recipient: rfc822;noc at Level3.net
Action: failed
Status: 5.0.0
Remote-MTA: dns; cluster5.us.messagelabs.com
Diagnostic-Code: smtp; 553-Sorry, your email address jtl at isc.org has been
553-blacklisted. Refer to the Troubleshooting page at
553-http://www.symanteccloud.com/troubleshooting for more 553
information.
(#5.7.1)

Sep 19 23:32:58 amstel postfix/smtp[93402]: ED44E1FCBC3: 
to=<noc at Level3.net>, relay=cluster5.us.messagelabs.com[216.82.250.51]:25, 
delay=6.6, delays=1.4/0/5.1/0.16, dsn=5.0.0, status=bounced (host 
cluster5.us.messagelabs.com[216.82.250.51] said: 553-Sorry, your email 
address dmahoney at isc.org has been 553-blacklisted. Refer to the 
Troubleshooting page at 553-http://www.symanteccloud.com/troubleshooting 
for more 553 information. (#5.7.1) (in reply to RCPT TO command))

-Dan Mahoney
(hat: isc.org operations group).

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