Regardless of what is on my server, there seems to be a limit that Thunderbird can manage for local storage of emails. Why should it matter how many emails are stored locally. I have plenty of room on my mail server and my disk storage. I don't have this problem on any of my Apple devices, only on Thunderbird which I run on Windows 7. It's not a matter of server capacity, because my server is fine. It seems to be an artificial limit by Thunderbird. Why is this so?