Cannot receive emails

Cannot receive emails


I cannot receive emails in my zoho account. Following is the error details - 


----- The following addresses had fatal errors -----
[...@....com]

Message will be retried for 4 more day(s)

Reporting-MTA: dns; mx.zohomail.com
Arrival-Date: Mon, 05 Dec 2022 21:46:07 +0530

Original-Recipient: xyz
Final-Recipient: xyz
Status: 421
Action: failed
Last-Attempt-Date: 5 Dec 2022 17:01:35 GMT
Diagnostic-Code: Host not reachable.

Please resolve.