Yahoo email addresses are failing in Zoho Desk

Yahoo email addresses are failing in Zoho Desk

Hi,

We have seen recent issues sending to a yahoo.com address. From the tickets...

Status: 421
Action: failed
Last-Attempt-Date: 14 Feb 2024 21:16:41 GMT
Diagnostic-Code: 4.7.0 [TSS04] Messages from 103.138.129.66 temporarily deferred due to unexpected volume or user complaints - 4.16.55.1; see https://postmaster.yahooinc.com/error-codes
Remote-MTA: dns; mta6.am0.yahoodns.net

This is, as far as I can tell, stopping all of these tickets from going to the recipient.