Creating mailbox on Exchange Server located in another child domain

Hi, would like to check if it is possible to create a user mailbox on an exchange server located in another child domain.

e.g

Forest root: example.local

Child Domain 1: child1.example.local

Child Domain 2: child2.example.local

Exchange Server FQDN: EX01.child1.example.local

Mailbox User: user1@child2.example.local

So i have the exchange server in child1 domain. Can i create a mailbox for user1@child2 on EX01.child1.example.local?

If yes, should it be linked mailbox or user mailbox?

Managed to find a few articles that mentioned that Exchange server in forest root can host mailbox for users in child domain. But how about exchange in child domain hosting mailbox for users in another child domain?

Thanks alot.