Hello

Lets say I don't have any issue with Required Servers and Hardware

I would like to know What the Maximum number of mailboxes I can Create in Exchange 2013 On premise , can it reach for 5 Millions ?

appreciate your help

Thanks

If you don;t have issue with Hardware, than definitely you can create 5 Million Mailboxes.
Are you really Planning to do it?

I will be more than Happy to be part of it :)