When I opened Thunderbird to get and read my new email I received this error message after I could see that Thunderbird had found new messages. "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." I checked the hard drive space on all of my hard drives and I have GBytes of space and in PREFERENCES for the hard drive, WRITE is allowed. In fact all items listed in Preferences is set to allow. I've rebooted the computer and even had Windows check my hard drive for errors and it found no problems. What do I now need to do? Thank you. Fred Berney