deactivate Check for new messages every 10 minutes
I think leaving Check for new messages every 10 minutes by default is a bad choice. If the users wants this, he should activate it.
It adds unnecessary load to Tor if the user left his desktop for a while or simply forgot to close Thunderbird. Checking every 10 minutes lets the mail provider guess how long a Tor session lasted. Its better to pull mails only on demand and cease any unnecessary transmissions afterwards.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information