Strange new behavior - up until two days ago, we were able to send and receive email via desktop email client (Entourage), now any attempt to send emails from Entourage generates an error message.

Incoming emails are still received OK within Entourage 

and sending/receiving emails works OK from all mobile devices.

Outgoing settings:

smtp.zoho.com

SMTP service requires secure connection (SSL) - checked

Override default SMTP port: 465 - checked

SMTP server requires authentication > Use same settings as receiving mail server - checked

PLEASE HELP!