Reader Logan Phillips offers up what turned out to be a bit of a brain bender. He writes:
I’m a writer who has built up quite a large amount of email over the last few years. I would like to keep this correspondence for reference in the future, but it’s not something I use everyday, nor do I need to have access to it in Mail.app everyday. What is the best way to archive emails for long-term storage?
Before we proceed I need to provide a little background. Let me start by telling you that although Mail 2.0 (the version of Mail that ships with Tiger) produces folders that bear the .mbox extension (which you’ll find by following this path: youruserfolder /Library/Mail/ accountname / mailboxname.mbox ), these .mbox folders are different from the .mbox files that accompanied previous versions of Mail. With earlier versions of Mail, an mbox file contained the entire contents of a particular mailbox—all the messages in your primary account’s Inbox, for example. Mail 2.0 works differently in that it stores messages individually as .emlx files within a Messages folder within a .mbox folder (purportedly this change was made so Spotlight could index the contents of Mail messages).
I’m keen on archiving old mail to another email client (and I’d like to thank Michael Tsai for putting that idea in my head with his E-Mail Archiving with Eudora and Mail.app article). The benefit is that not only do you clear out old mail from your regular email client (and, thus, potentially goose its performance), but you can then also browse that old email in a program meant for email browsing. I mean, honestly, who wants to sift through a single enormous archive of email messages in a text editor?
Again, so what?
I’ve been unable to find an email client other than Mail 2.0 that will read these dratted .emlx files, which pretty much puts the kibosh on my preferred archiving scheme. (These files can be read with a text editor, however.)
The trick then is converting the .emlx files to a format that can be read by another (preferably free) email client. I’ve managed to find a way to do just that with a copy of CosmicSoft’s donation-ware emlx to mbox Converter. It works like this:
Launch emlx to mbox Converter and then launch Mail 2.0.
In Mail 2.0 select a mailbox you want to archive and drag it to the Desktop to create a .mbox folder. (Alternatively you can create a new folder in Mail 2.0, toss into it any messages you want to archive, and drag that folder to the Desktop to create the .mbox folder.)
Switch to the Finder, open the .mbox folder and then open the Messages folder within to reveal the .emlx files. Select all of the .emlx files and drag them into emlx to mbox Converter’s window to add the files to the utility’s list. Click Save mbox.
This clumps the many .emlx files together into a single, old-fashioned mbox file (found within a .mbox folder created by the utility) that can be read by most email clients. Name the .mbox folder and save it to the Desktop. Open that .mbox folder in the Finder and rename the .mbox file within to something catchy like “Archived.”
Now for the email client.
Because it’s free and easy, I chose Mozilla Thunderbird as my archived email reader. Once downloaded, set up a single user account. (Don’t worry, you never need use it to retrieve email, though once you try it, you might like it.) Quit Thunderbird and travel to youruserfolder/Library/Thunderbird/Profiles/ defaultprofile /Mail/Local Folders.
Drag the “Archived” mbox file (from within the .mbox folder you created with emlx to mbox Converter) to this Local Folders folder. Launch Thunderbird and breathe a huge sigh of relief when you find that your archived mail (and its attachments) appear when you select the Archived entry in Thunderbird’s Folders list.