Hi Michael French, I know how stressful it feels when something as simple as sending an email gets blocked especially after you’ve already cleaned up files.
Empty OneDrive Recycle Bin clear large emails and attachments in Outlook delete OneDrive sync cache then sign out and back in so your storage refreshes and the email sending issue disappears.
On the Microsoft account storage page what are the top two storage consumers OneDrive vs. Outlook and how many GB are still sitting in OneDrive Recycle Bin after you emptied files?
Best regard
Lucky