You can save individual, multiple, or even entire folders of emails from Mail.app as an RTFD document, along with attachments.

1. Select email(s) or folder you want to save.
2. Choose “Save as…” from File menu.
3. Navigate where you want to save the file. Turn on “Include Attachments” and choose “Rich Text Format” from popup. Click “Save”.

If the email you selected had attachments, the resulting document will be an RTFD. You can either open it in Preview, or right-click on the RTFD and choose “Show Package Contents” — you’ll find it’s a folder with all the attachments and a TXT.rtf.

You might try using Ready-Set-Do!’s Mail Rule. You can set this up so that emails go directly into your file system. A new folder is created with the subject line of your email and the text of the email — along with any attachments — get saved in that folder. And thus it is easily searchable by Spotlight. It works very well. A new one that works with selected mail messages will debut sometime next week.

Hey, RTFD could be the answer. Thanks, Robert! One question: When I save to RTFD document, I only get the enclosed documents to show as icons; i.e. no file names. Is this how it’s supposed to work? I can see the enclosed file names when looking the package contents, though. And of course they are searchable via Spotlight, which is crucial.

Todd, I’ll take a look at R-S-D also… if it’s supporting Leopard, which I’m planning to install during the weekend ;-)

For some reason I can’t save attachments anymore with the RTFD document in Leopard Mail. It worked fine in 10.4. Is it just me or is this a bug in Leopard?

If you drag an email from Mail to a location on your Mac (Desktop, Documents folder etc) it creates a .EML file, which includes the attachments.