Hey there! It sounds like you're facing an issue while trying to download email messages in Thunderbird. The error message "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox" usually indicates a problem with permissions or available disk space. To fix this, first, make sure you have enough space on your computer. Then, check if Thunderbird has the necessary permissions to write to your mailbox. You might need to adjust folder or account settings. If you're unsure, you can find more specific steps in Thunderbird's support resources.

How do you check to see if Thunderbird has the necessary permissions to write to your mailbox? Where do you find Thunderbird's support resources? The how to do this is what I'm having the problem with.  :-) I deleted a large number of messages so that if space was the problem that should have opened up the space. Next is to figure out where and how to fix the write privileges. I am using Gmail forwarded to Thunderbird.