SMTP Authentication in your mail client

SMTP Authentication in your mail client

hi it is the first time someone is sending me an email and it is embarrassing that they cant do so
all they get is

The response from the remote server was:

550 Please turn on SMTP Authentication in your mail client. mail-io1-f48.google.com [209.85.166.48]:37461 is not permitted to relay through this server without authentication.