Email solution for multiple domains

Hi, I’m wondering if anyone can recommend an email solution for our small hotels.

We have four domains, eg; hotel1.com, hotel2.com, hotel3.com, hotel4.com

We’d like to have maybe a dozen or so email mailboxes within each domain, eg; manager@hotel1.com, info@hotel1.com, manager@hotel2.com etc etc

Each mailbox needs its own username and password assigned. No email forwarding.

Thanks