Secondray user has no own Calendar and cannot be added to Staff in Bookings

Hi Zoho Team,

I have a free mail license where both the primary email-address and the secondary email-address are hosted by my local provider, where I changed the DNS record to Zoho, so that both addresses could receive email on the Zoho- email platform.

Email works great: emails from both uses can be send from the mail box. I encountered following issues (and lost a lot of time trying to solve them):

the is only one calendar, for th eprimary email-address; accepted meeting invitations for the secondary primary email-address end up there = in the calendar of the primary email-address
I cannot add the secondary email-address as user to Zoho CRM
I cannot add secondary email-address as Staff to Zoho Bookings
I cannot delete the secondary email-address from the account - in order to create a separate new account for this email address

How can this we solved?

Philip