Unique Contact Email requirement to sign up to Zoho Mail hosting service

Unique Contact Email requirement to sign up to Zoho Mail hosting service

Hello,

When I want to create multiple accounts (one per domain) for hosting mail at Zoho every time I need a unique Contact Email.

Would it be possible to always allow to use the same email address instead? I can't see any security issues with that solution whilst it would be very convenient if somebody wants to have all activation emails sent to the same address.

Please advise at convenience.