Why is my .thunderbird folder so big?

Question

This is absolutely horrifying. I'm using Ubuntu 12.04 and I just found out my .thunderbird folder under my user home directory is 7.4 Gigabytes... However I'm pretty sure I'm using IMAP for all my email accounts, so why is it so huge? And what should I do? Can I just delete the .thunderbird folder?

Thank you so much for help!!

Answer 1

For IMAP accounts, offline folders are enabled by default, so a copy of all mail is kept locally.

To disable it:

1. go to Account Settings -> Synchronization & Storage and uncheck "Keep messages for this account on the computer".
2. under Account Settings -> Server Settings, take note of the relevant "Local directory".
3. exit Thunderbird
4. in that "Local directory" and it's subfolders, delete the mailbox files (the files which have no extension). But keep the .msf index files and the .sdb files.

You may also want to disable "Global Search and Indexer" under Preferences -> Advanced -> General.

See http://kb.mozillazine.org/Minimize_the_size_of_a_profile for more details.

Answer 2

It is probably cache and emails you read, thunderbird needs to download them for you to read, even if you use IMAP. You can start by cleaning the cache: http://www.techiecorner.com/1737/how-to-clear-thunderbird-imap-cache/

Or you can use compacting: http://kb.mozillazine.org/Compacting_folders

Answer 3

It seems that you are storing all your emails and attachments (7.4 GB of them). By default, thunderbird downloads all emails and mirrors them locally. If you delete some of the bigger emails in the cache, this will decrease the size of your thunderbird directory.