Receive Calendar's altert in Zoho mail

When I registered to Zoho there was not yet Zoho Mail, so I put a Yahoo mail address.
Now I have a Zoho mail address and I would like to receive Zoho calendar's alerts there and no more in Yahoo. Is it possible to delete the Yahoo address and use the Zoho address only?
I have tried to, but without success! I have also cancelled that Yahoo address to see if there was a chance to let Zoho know that that address is nomore valid.