You are sending an email to a domain protected by the Symantec Email Security.Cloud service and are receiving a non delivery receipt (NDR) stating the email delivery failed.
553-mail rejected because your IP is in the PBL. See http://www.spamhaus.org/pbl
This error message indicates that your public IP address from which you are sending emails from has been put on the Spamhaus PBL block list.
You will need to submit a request to have your IP removed at Spamhaus Project - PBL.
The delisting process normally takes about 1 hour. If the problem persists, please contact the recipient by other means and request that your email address be added to their Symantec Cloud approved senders list.