MacMail/GoDaddy

Hiya!

This is my first question here, so hopefully I don't appear too uninformed.

MacMail works great for me and for all of my emails, save the most important one...my business. I have to use a godaddy email address, and recently they made a change from workspace to microsoft 365 and my inbox has been a shambles ever since. I file all of my emails into specific project folders. Sometimes the emails have PDFs attached or photos, sometimes big long threads. Since the change, if I file an email and then go back later to reference it, or find any information, some emails (in the thread) will be gone. Or better described, the email is there, but there is NO CONTENT inside of the email. GoDaddy simply says that MacMail is third party, so this is my fault, but I never had that problem before the change. And I can no longer search for a specific keyword or person. That option is no longer possible, and i don't know why. I need all of my emails, and i need to be able to go back and reference them. Can someone please help me and let me know what I am doing wrong?

I appreciate any help/guidance you can give to me.

Thank you so very much!!