Cannot see received mail after migrating account to new mac
I bought a new Mac Pro 2019 and migrated my user account from my old mac to my new mac pro using the migration assistant.
After migration was completed, when I open mail on the new Mac Pro 2019 I can see my mail folders and all the mails I received before the migration.
I can connect to my mail account and I can see new mail being received in the connection window.
However once this new mail has been received I cannot not see it in any of my mailboxes. I have no idea where it goes or how to make it show up.
Thank you for your help.
Mac Pro, macOS 11.2