SMTP Error 471

Description: An error of your mail server, often due to an issue of the local anti-spam filter.

What does this mean?

This description is pretty straight forward. Your server or (remote mail server)’s anti-spam filter has prevented this message from proceeding.

How to fix SMTP Error 471?

Attempt disabling outgoing anti-spam filters from your server. Or if using a remote mail exchange, contact the server administrators.