Spam filtering error codes for Email Security

Products

• Email Security.cloud

Issue/Introduction

This article describes the common errors that we can see when attempting to deliver an email to a non-customers mail server. These errors would be generated be the recipient's side and their Spam Filtering/Content Control gateway.

The list of errors contains the following error communicates but it is not limited only to them:

• 550 5.7.1 Message rejected as spam by Content Filtering
• 551 Sender is on domain's blacklist
• 5.7.1 Recipient not authorized, your IP has been found on a block list
• 5.7.1 Message Rejected as spam by Content Filter
• 554 Rejected due to banned content
• 554  Rejected due to spam content
• 550 Permission denied
• 550 Connection refused
• 550 "5.7.0" Mail relay denied

 

 

Environment

Email Security.cloud

Resolution

The end recipients would need to reach out to their internal teams and possibly their Email Security service provider for them to perform an investigation behind these errors and what might be causing them.