I am trying to invite people to become members of a personal group that I created.  I am able to invite zoho users with no problem. I am able to send invitations to non-zoho users that do not have their domains hosted on zoho, although they are not able to accept my invitation unless they sign up for a zoho account.

But, when I try to invite someone with an email address that is part of a domain where the email is hosted through zoho, I am having a problem.  After I send the invitation the screen says invitation sent successfully.  However, no invitation is actually sent to the person and the person's email address does not show up in the pending invites section, no matter how many times I refresh the page.  It's as if the invitation was never sent.

I am able to invite people that are in my organization even though the email address domain is hosted on zoho, but I am not able to invite people from other organizations that have email addresses hosted on zoho.  I understand restrictions are placed on who can be invited to organization groups.  But, it was my understanding that personal groups were not limited to members of your organization (hence why there is a link to invite friends).  And, if I was able to send invitations to people who are non-zoho users, why can't i send them to people who are zoho users through their domain-based email addresses?

I tried creating a personal group and sending the invitation to another user (with domain-based email hosted on zoho so therefore a zoho user).  When this didn't work, I had a friend try the same thing with their zoho hosted business account, and they had the same problem.  I need to create the personal group so we can share calendar, contacts, discussions, etc.  Please help me fix this problem ASAP.  Thank you very much!