kycno email not working

Good day,

I have contacted the bank via secure chat to report that kycno-usuage at fnb(.)co(.)za doesnt work. The agent gave me another email I could use to submit the documentation required and it seemed to have worked. Today I got a sms telling me that the card has been placed on hold due to outstanding documentation...

Please sort out your email server. Here is the error message:

"Address not found Your message wasn't delivered to *** because the address couldn't be found or is unable to receive email. The response from the remote server was: 550 #5.1.0 Address rejected."