This is a continuation of yesterday's question, but I'm getting frustrated with Outlook and it's little glitches, and people want spam filtering. Most of our users have thousands upon thousands of messages stored in folders (some have 70k plus), and is why we don't use IMAP. Is Thunderbird stable enough and 'corruption-proof' to handle such loads? No one really uses any Outlook specific features such as calandar and the like. I personally like it, but don't know how it will do. Any comments?