Confirmation email not being sent

Confirmation email not being sent

Hello,

I've been able to sign up on Zoho fine (free account).  I can set up users and groups etc (they get their emails fine).  What is not working is the confirmation email is not being sent (to authenticate the original account registration).  I have tried multiple email accounts (that are verified working) and none of them work. 

Any suggestions?

Thank you,
Rene