Private posts saved as drafts

Hello,

We tried to set Postie to use the “private” status as default, but for some reason, some of the emails are stored as private while others are saved as drafts. They do not contain the keyword “status: draft” in the body of the message.

Is there any way to troubleshoot this? Or perhaps force Postie to save all posts as private via wp hook?

Thanks!
Petr