I've searched (and continue to search) for an answer to this. I love Lion's mail application, and especially its integration with Spotlight. The ability to fan through a bunch of search hits using Cover Flow is a lifesaver for me! It's a marvelous capability that brought me firmly into the Mail.app camp after using several other email applications. Really good stuff. Problem: My email records go back more than a decade, comprising hundreds of thousands of emails, including to groups of which I'm either a member or an administrator. It is important that these emails be accessible to me, and quickly searchable. Mail.app + Spotlight fills the bill admirably for me. But my inbox is growing too swollen and is bogging down my system. Right now, I triggered some action (I have no idea how) and my machine is "Writing changes to disk - 20927 of 150425 messages". This is a common occurence and will go on for an hour or so. And when I reinstalled Lion recently it took overnight for Mail to import my previous inboxes! Too darn many emails. What I need to do: Take all emails older than a year and put them in some sort of archive folder where they don't clutter up Mail's everyday activities but Spotlight can find them (and Mail can open them when asked to when previewing or opening in Spotlight's search results). I have one gmail (IMAP) account, three POP accounts, and a new iCloud accout I'm not using much yet. I want to include the gmail and iCloud emails in my archive for local searching. I have plenty of disk space. My question for the community: What is the best way to locally archive old emails, including attachments, so they're still searchable and openable but don't bog-down Mail? I have searched (and continue to search) for solutions but am finding suggestions that plain don't work, such as "drag old emails to the desktop and Mail will create a file" (that'd be great, but it doesn't work, at least in Lion). Mail's own Archive function spits an error for the gmail messages, The message "[subject] could not be moved to the mailbox (null). The destination mailbox does not exist.. This place has never steered me wrong, so I'm hoping for some suitable suggestions! Thanks in advance.