Issue mails duplicated themselves when I tried to delete them

[Vamt]

Hi,
I've tried multiple times to delete some mails, but instead of being deleted, those mails duplicated themselves.
(I linked Plesk to Mac Mail; can this be the issue?)
What should I do to fix it?
Please help.
Thank you

 

[AlexanderK]

I have the same problem and need help also. But like I see, no one want to answer...