Hey KevinTheJedi
Thanks for your answer.
My setting is already "Delete emails".
And there's no email stuck in my mailbox, it's all empty.
However, each time I get this error message, there is a ticket that is created, but when I click on it, the body is empty.
For example, I just got this error message again.
I went into the mailbox and it's empty.
Then I go to the tickets and there's a new ticket that's been created, with a thumbnail icon.
But if I click on it, it gives the following result (sorry for French):