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.