Delivery Status: Remote Server returned '554 5.4.0 < #4.7.0 smtp; 421 4.7.0 [TSS04] Messages from [IP] temporarily deferred due to unexpected volume or user complaints

Products

• Messaging Gateway

Issue/Introduction

Messages delivery to a particular domain are failing with the Message Audit Logs showing a delivery failing with the SMTP response

554 5.4.0 < #4.7.0 smtp; 421 4.7.0 [TSS04] Messages from 192.0.2.100 temporarily deferred due to unexpected volume or user complaints - 4.16.55.1; see https://postmaster.yahooinc.com/error-codes>'

 

Environment

Release : 10.8.0

Cause

Messaging Gateway is attempting to deliver messages to a destination server which will not accept them due to either rate limits or end user customer complaints.

Resolution

Messaging Gateway cannot deliver mail to a server that refuses to accept it. Usually these email delivery rejections contain some information regarding the cause and a link to the destination mail server's policy. To resume sending email to the destination domain, you will need to comply with the receiver's email policy.