Importing large Apple Mail mailbox

I have an Apple Mail mailbox with 41,618 messages. I want to import the messages into EagleFiler and remove them from Apple Mail. The message are from a pop server that I have now discontinued (after moving to O365). If I use the F1 key capture message, I see the spinning ball of OSX and it appears no messages are transferred into EagleFiler. Is it possible to import this many messages? Do I highlight the messages then hit FN-F1 or do I somehow drag the inbox on the left side of Apple Mail into EagleFiler? I tried dragging the Finder folder containing the emails into EagleFiler and leaving the import to continue overnight. However when this import technique had eventually finished, I was unable to search for emails (ie no search results were presented). Upon searching I would see a yellow color in the EagleFiler records area. Individual emails could be inspected (although not searched) in the sense that I could see their contents, however they were listed without information such as their from, to, or sent date being displayed in the records list (instead only their message code was displayed in the list). I have downloaded the import script but not tried it yet. The instructions about the script do not seem to recommend it for mass email imports. Is that correct?
Overall, I am really hoping for some advice about the best way to handle large Apple Mail inbox repositories please. I have not yet purchased EagleFiler but plan to do so if I can just work out how to get large amounts of mail into it successfully.
Thanks,
JR

No, it’s not normal to get the spinning beachball. If you see that, please send in a sample report.

Yes.

It sounds like maybe you didn’t give EagleFiler an entire .mbox folder to import. I asked for more information when you contacted me via e-mail.

Importing via script works fine, but I think in most cases it’s not very convenient for importing e-mails. People don’t always want to import an entire mailbox. And it’s usually desirable to have the messages selected in Mail so that you can delete them after importing. So at that point, why not just import via the capture key?

After talking with Jason, we’re not sure why Mail was beachballing, but he was able to directly import his entire inbox into EagleFiler by dragging and dropping the folder:

/Users/<username>/Library/Mail/V3/POP-username@server/INBOX.mbox

Very happy

Michael, thank you for your timely, detailed and meticulous replies to my questions. I feel the problems I experienced are now fully resolved and I am using EagleFiler with both confidence and pleasure.

I had exact same problem
I was able to resolve problem by breaking down my large email import into three parts rather than all at once. As a separate but possibly related issue, EagleFiler also appeared to get stuck on a few old emails which I deleted and may have been corrupt. Our company has experienced similar problems in the past 30 years with Excel, Filemaker Pro, and other database programs, often on files that were created before the year 2000 (maybe even possibly a y2k issue). One currupted data file in a batch of thousands can sometimes screw up the whole import process.

It should skip over any e-mails that are unreadable. If you still have any of those messages, I would be interested in seeing them for testing purposes.