I have a domain email address X@DOMAIN.com

I've migrated MX records to zoho and the imap service is excellent.

To add Y@DOMAIN.com can I simply add user in zoho account or do I need to add user via my domain host.

I'm slightly confused because when I add a user it asks me for an email address.. although creating the email address is the aim not the requirement.

Thanks for and specific advice..

Excellent service