If you are a Company and you have to choose a provider for your mailboxes, probably you will choose Google Workspace or Microsoft Office 365.
Both services are great but maybe you can evaluate also some less popular alternatives such as Fastmail, Privatemail, and Qboxmail.
Fastmail is an Australian provider that offers different Mail plans with a focus on User Privacy. More information at: https://www.fastmail.com/.
Privatemail is a simple and cheap Mail service made by Namecheap with flexible solutions for personal and business mailboxes.
More information at: https://privateemail.com/.
Qboxmail is an Italian Company that released a product useful to manage your mail service with a powerful dashboard and business tools (included Agencies Whitelabel). More information at: https://www.qboxmail.it/.
I hope that this article will let you find the perfect service for your mailbox! ;)