I have an email account that keeps getting below email while sending to a certain domain. Other accounts are able to send to same exact domain without issues.Here is the log

--> RCPT To:<user@recipientdomain.com>

  <-- 550 5.7.1 <user@recipeintdomain.com>: Recipient address rejected: ERS-RBL.

  --> RCPT To:<user@recipentdomain.com>

  <-- 550 5.7.1 <user@recipientdomain.com>: Recipient address rejected: ERS-RBL.

  --> QUIT