550 error SMTP Authentication in your mail client.

550 error SMTP Authentication in your mail client.

Hi,

When I try to send emails to zoho mail from other mail servers the following happens;

The error that the other server returned was:

550-Please turn on SMTP Authentication in your mail client, or login to the

550-IMAP/POP3 server before sending your message.  mail-qg0-f48.google.com

550-[209.85.192.48]:45780 is not permitted to relay through this server without

550 authentication.



Can you please help asap?


Thank you for your time and consideration,


Joaquim MIro