How to setup email for US division when domain is in China?

Hello,

I'm hoping for some guidance on how to properly setup email for my team in the US with our company's domain being in China. From what I have tried thus far with Google Workspace and Microsoft Outlook, we would need to "migrate" everyone to the new system. Our company currently uses 263.net for the domain provider. I am able to access email through Outlook using IMAP, however, it doesn't pull in a calendar. So if I add an appointment, it creates it in Outlook, but to the local computer only. I'm trying to figure out a solution where I can access both email and calendar across multiple devices. It would be great if I could also share files and team member calendars too, but not required. Any advice is much appreciated!