Hi Coreyoga,
We appreciate you reaching out to us. We understand that you are experiencing issues deleting or moving some Exchange emails after switching to a new provider.
We’d like to gather additional details that may help us be in a better position to assist you.
Is your Exchange Mail account still active and signed in on your device?
If no, what you're experiencing is expected behavior.
IMAP typically stores the message on the server of your provider, and synchronizes the message across the devices you are signed in.
If this is the case, we recommend that you reach out to your previous email provider to see if there is any way you can still get your emails.
Take care!