I started a company years ago and one of the partners setup google to handle the email. Our logins were joe@company.com, no gmail addresses. We parted ways years ago and I started another company. I just went into my google admin and had the same google account handle the email of the new company. What I would like to do is either set google up where my new login is joe @newcompany.com and move all my existing folders (i know google calls them labels) to the new account. I am not worried about getting any emails to the old account. Second option would be to move everything to Microsoft. How do I go about doing this? I thought I was fairly technically inclined but not opposed to paying someone to do this for me either.

I can sit down and take a look and provide some guidance. I use both Google Workspace and Microsoft 365 for different domains and have migrated from one to the other as well.

Another alternate might be ProtonMail. They also include a utility for importing e-mails from other services.