Undeliverable or Blocked Messages -- Verizon FIOS

When I send emails from my Helm server to an iCloud address, my work address, or even Helm Support - I get an undeliverable message as follows. Is my IP blocked by Verizon how can I get off of this list?

This is an automated email from your Helm Server.

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 information about why this might happen visit our support
article here:

Helm

<nilsa2014@icloud.com>: host mx01.mail.icloud.com[17.57.154.23] said: 550 5.7.1
Mail from IP 173.66.45.236 was rejected due to listing in Spamhaus PBL. For
details please see http://www.spamhaus.org/query/bl?ip=173.66.45.236 (in
reply to RCPT TO command)
Reporting-MTA: dns; helm.airmailpost.net
X-Postfix-Queue-ID: 91A6312C0001
X-Postfix-Sender: rfc822; cstockel@airmailpost.net
Arrival-Date: Sun, 6 Mar 2022 02:49:28 +0000 (UTC)

Final-Recipient: rfc822; nilsa2014@icloud.com
Original-Recipient: rfc822;nilsa2014@icloud.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; mx01.mail.icloud.com
Diagnostic-Code: smtp; 550 5.7.1 Mail from IP 173.66.45.236 was rejected due to
listing in Spamhaus PBL. For details please see
http://www.spamhaus.org/query/bl?ip=173.66.45.236

Anyone run into this with Verizon?

UPDATE - They fixed it with a firmware update. All is working well now.