Manually reinstall Apple Mail Plugin - HowTo?

Hi, thanks for your post.
Indeed DTPO did not figure in the Full Disk Access list, so I added it manually.
First tried it with DTPO v2, as this did not work, also tried it with v3, but this does not work either?

In the end, there is no save mail message to DTPO in the Mail.app menu…

Any other idea’s?