Do you actually want to import your whole inbox? Or only the messages that are new since the last import? The advantage to using the rule is that you will naturally not have to deal with duplicate copies of messages since it imports the messages as they are received.
The way I do this is to select all the messages and press the capture key. After it’s finished importing, I press Delete to remove the messages from Mail. (Or you could use the Archive command, I suppose.) That way, the inbox (and other key mailboxes) only ever contain messages that have not been imported to EagleFiler, so it’s easy to keep track.
If you need a fully automatic solution, you would basically:
Keep EagleFiler running, with the desired library open.
In the Finder, click on the Go menu, hold down the Option key, and choose Library. Inside the Library folder, find (or create) the “Application Scripts” folder. Inside Application Scripts, find (or create) the “com.apple.mail” folder. Place the downloaded file in the “com.apple.mail” folder.
In Mail’s preferences, create a new rule at the top of the list. Set the condition to “Every Message” and the action to “Run AppleScript”; then select the Import From Apple Mail file as the script.
As Mail receives new messages, it will automatically send them to EagleFiler for archival. (Note that this will only happen for messages that Mail sees as new; if you mark a message as read on your iPhone or another Mac, Mail will not see it as new, so it will not apply the rule, and so the message will not be imported.)
When I capture Apple mail, either one at a time or a group at a time and direct them to a folder, there appears a small inbox icon, which I have to open and drag the contents to the main folder so they all visible – effectively moving them up one level. Is there a way to capture into one of the EF folders without having them encased in the inbox icon?