I'm trying to set-up our Prestashop 1.6 SMTP mail settings but keep getting the message:

Error: Please check your configuration

I am using these settings:

smtp.zoho.com

sales@domain.co.uk

password (which is correct when logging in directly to Zoho Mail)

SSL

465

When I use my own Gmail SMTP settings the test mail is sent, only when I use Zoho mails settings they don't. 

I have found loads of posts on this forum with plenty of people having the same problem but no concrete solution, can anyone help?

Thanks