Hi Thunderbird community, I am trying to setup a 2.0GB USB drive with a copy of Thunderbird portable. The problem I have is that the default behavior grows the local cache (profile / ImapMail) out of control, fills up the key, and causes failures. So far I have: -Changed "Compact all Folders when it will save over" 1 MB -Set "Override automatic cache management" to 250MB -deleted and resynced the IMAP files in case an error was causing a failure to compact. My local cache of IMAP folders still grows out of control. What I need is a setting to make Thunderbird not keep a local drive cache and just work out of RAM. Or at minimum hard limit the cache to around 1.2 GB. Does anyone know how to do this and would be willing to share? Thanks in advance, John N.