Getting the error 451 4.7.500 Server busy

Hello,

The last 2 days we are experiancing an issue that our emails are not being send out of the ERP system we are using.

while talking to *****-nl.mail.protection.outlook.com [52.101.2.....

   >>> DATA (EOM)

   <<< 451 4.7.500 Server busy. Please try again later from [81.169.146.......].

       (S77719) [AM4PEPF00025F98.EURPRD83.prod.outlook.com

       2024-11-15T00:36:18.408Z 08DD001D8C5D9288]

I have partially removed the IP here but we are using Strato hosting server and it normally worked last 2 years.