EXPERIENCED ONLY ~ Export 10-15 email boxes (I'm transfering to new domain Registrar)

We're changing Registrars and upgrading to new server with Namecheap. (server already purchased)

This is one domain with 10-15 associated email boxes (emails go back many years and we want to keep this data)

NOTE: during transfer, we need to be able to do "send-receive" to continue receiving email so none will be lost (Windows 11 based EMAIL CLIENT)

Here's what I need completed:

1. I need to export those 10-15 email boxes (complete) from GoDaddy's Microsoft Office 365 to an EMAIL CLIENT (NOT OUTLOOK) (NOT OUTLOOK)

2. I will hold them at EMAIL CLIENT for safekeeping until my new server is set up and domain is transferred.

3. Once I set up (NEW) Domain with associated emails, you will transfer the emails to their respective email boxes.

4. IMPORTANT NOTE: I do NOT want ANY emails deleted in the process of moving to new registrar.

5. Work will be done through Screen Share, I will be online with you during transfer.


6. Question: Which EMAIL CLIENT do you recommend (other than Outlook)? I will set up account.

EXPERIENCED ONLY