Common Error Messages

This page provides an index of common error messages you might encounter when using MXroute email services, organized by category.

Authentication Errors

550 Authentication Required

This error occurs when attempting to send email without proper authentication. The full error message typically reads "550 authentication required" or similar.

Sender Verify Failed

This error happens when the server cannot verify that the sender address (FROM address) is valid on the server attempting to send the email.

Delivery Issues

No Such Recipient Here

This error occurs when sending to an address that the server believes should exist locally but doesn't. Common during domain migrations.

Connection Problems

More connection-related errors coming soon.

Administrative Blocks

Address Blocked by Admins

Errors indicating "Your sending address has been blocked by admins" or "Your recipient address has been blocked by admins" mean that specific email addresses have been blocked at the server level due to policy violations or abuse.

More error documentation coming soon. If you encounter an error not listed here, please contact support with the full error message and timestamp.