We work with thunderbird on a corporate network. Very often letters between thunderbird users come with broken attachments (pdf, jpeg). Letters can also come completely empty and when you click on a letter it shows it as read, and then it again appears in bold as if it weren’t read. And when forwarded to another user, the message may open normally. Repairing the folder and deleting the entire cache, with authorization again, It didn’t help. We have the latest version of the program. How can I solve these problems?