About this tool
Paste a bounce message to identify SMTP codes and read troubleshooting guidance.
Review the result for your task before using it elsewhere.
Receiving-server diagnostics take precedence. No live delivery test is performed.
Frequently asked questions
How do I use this tool?
Paste a bounce message to identify SMTP codes and read troubleshooting guidance. Review the result for your task before using it elsewhere.
What limitations should I check first?
Receiving-server diagnostics take precedence. No live delivery test is performed.