undeliverable email question

[sccc]

A notification email generated by our phpBB that confirmed a new registration was returned to admin with error message copied below. I can't tell for sure if it's us or them that's blacklisted?

If it's us, it might be useful for sonic.net to know.

Any informed response welcome.

Thanks in advance,
-Peeter

Forwarded message -------------------------

From: Mail Delivery Subsystem <MAILER-DAEMON@a.hosting-out.sonic.net>
Date: August 5, 2012 10:39:33 PM PDT
To: <sccc@sonic.net>
Subject: Warning: could not send message for past 4 hours

   **********************************************
   **      THIS IS A WARNING MESSAGE ONLY      **
   **  YOU DO NOT NEED TO RESEND YOUR MESSAGE  **
   **********************************************

The original message was received at Sun, 5 Aug 2012 18:24:55 -0700
from d.custweb.sonic.net [64.142.100.58]

  ----- Transcript of session follows -----
... while talking to s21.vom.com.:
RCPT To:<wendy@follenandcompany.com>
<<< 451 IP_69.12.221.232_blacklisted_by_barracudacentral.org
<wendy@follenandcompany.com>... Deferred: 451 IP_69.12.221.232_blacklisted_by_barracudacentral.org
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old
Reporting-MTA: dns; a.hosting-out.sonic.net
Arrival-Date: Sun, 5 Aug 2012 18:24:55 -0700

Final-Recipient: RFC822; wendy@follenandcompany.com
Action: delayed
Status: 4.3.0

Remote-MTA: DNS; s21.vom.com
Diagnostic-Code: SMTP; 451 IP_69.12.221.232_blacklisted_by_barracudacentral.org
Last-Attempt-Date: Sun, 5 Aug 2012 22:39:33 -0700

From: <forum@envirocentersoco.org>
Date: August 5, 2012 6:24:51 PM PDT
To: "wendyfollen" <wendy@follenandcompany.com>
Subject: Welcome to "enviro/forum"
Reply-To: <forum@envirocentersoco.org>


Welcome to enviro/forum forums

Please keep this e-mail for your records. Your account information is as
follows:

(snip)

[kavan]

barracuda is blocking the web server IP on the recipients end. I went ahead and submitted a removal request with them though I'm not sure how long that takes to process or if they'll honor the request.

[kavan]

They have removed it for 30 days at which time they will re-evaluate. Unfortunately due to the nature of their RBL and the fact that this is a shared web hosting mail server I can't really promise that it will not get re added in the future.

[Guest]

Why do they block in the first place? Maybe 'barracuda' is the name of a mail setup which kills all except pre-screened incoming?

[pv]

Meant to add "thank you" before hitting Submit, kavan