SMTP 550 5.4.1. — 9th edition: access.
What does this error mean?
The server refuses routing or access to the recipient.
Probable causes
- connector.
- Restricting.
- routing.
Verification and resolution
- Read full text.
- check connectors.
- control accepted field.
Precaution: The supplier can enrich this code with a more precise cause.
Quick diagnostic.
To diagnose SMTP 550 5.4.1 in the Email field, start with the following check: Read full text. Then compare the result to this probable cause: connector. Save the context and the time of appearance to compare behavior before and after correction. Priority level indicated: High.