Mail for Mac OS X format is not the same as mbox files

I think the title says it all, but the problem is bigger than that. The whole idea that the last 3 or 4 letters of a filename are an indication of underlying file format and structure is flawed. More than flawed, it’s wrong, but 3 decades of MS-DOS (yes, it’s still part of Windows) and its usability nightmare known as filename extensions is hard to overcome.

Interestingly, I don’t blame Microsoft for this particular confusion though, since it was Apple that broke the generally accepted, or de facto, standard in this case.

With the release of OS X, Apple introduced a new kind of file — or really a folder that acted and looked like a file to the user — called a package. The idea was that the insides of certain folders were only for system usage and should be hidden from users. For example, applications and all the various libraries and resource files and executables were packaged into a .app folder. To the end user, this .app folder looked and acted like a standard file and it could be double-clicked to launch the application. Early versions of Mac OS X even hid this package extension from the user, but to this day, to see the contents of a package, you have to “right-click” or “control-click” on the package and select “show package contents” to see what’s inside.

I have had 2 big problems with this new package construct:

1. No other OS has this construct and writing cross-platform code to deal with it is more difficult than it should be.
2. The Mac OS X file open/save dialogs do not hide the contents of the packages the same way the Finder does. Being that Mac OS X is otherwise very particular about consistency in its UI, I call this a bug.

Now, back to the topic of this post, Apple’s Mail application for Mac OS X uses “.mbox” as the package suffix for the folders that hold email message files. This is in direct conflict with the de facto standard of using “.mbox” as the file name extension for standard mbox files, and this creates incredible confusion for Mac and PC users alike when they are looking to convert their mail to or from mbox format or Mac OS X Mail format. In particular, Mac users looking to import mail into Mac OS X Mail get very confused with this and Apple should really do something about it. To make matters even more confusing, back with the release of Mac OS X 10.4, Apple removed the “package-ness” of the .mbox folders and now users can browse their contents freely. So, since these folders are no longer packages, why do they still need the .mbox name extension? Again, inconsistency.

So, to help deal with this confusion, I offer up these 4 rules of thumb:

• Mac OS X Mail folders are not Standard mbox files.
• Standard mbox files are not Mac OS X Mail files.
• If you have a folder with a name that ends with “.mbox”, it MAY be a Mac OS X Mail folder, but it is DEFINITELY NOT a standard mbox file.
• If you have a file with a name that ends with “.mbox”, it MAY be a Standard mbox file, but it is DEFINITELY NOT a Mac OS X Mail folder or file.

I hope this helps.

Just got a kind note from Mike, a Mac user, saying that Emailchemy was the only Mac-based method he could find to convert his Windows Outlook PST file to Mac OS X Mail. 1GB in 20 minutes, not bad at all.

Anyway, he wrote to also report another quirk in Mac OS X Mail’s import feature. I say “another” because I’ve already noted (and reported to Apple) a few others. The issue he reported was that when importing mbox folders in Mail 2.0 format (Mac Mail .mbox folders are not the same as standard mbox files), Mail will import all the folders but some folders that are deeper in the hierarchy have all their messages show up blank. Mike reported that importing mbox folders in the Mail 1.0 format worked fine, however.

The problem with the Mail import bugs (I’m not calling them quirks anymore) is that they are often hard to reproduce and there may only be a few other users who ever see this issue.

This is why I recommend using Emailchemy’s embedded IMAP server (the IMAP ImportServer tool) if you can. It bypasses the import wizard by providing you a desktop mail server that you download your converted mail from. It’s as simple as creating a new email account and downloading the mail.

Aside from the bugs in the import wizard, I like using Mac OS X Mail. It’s what I’ve been using for the past several years and I haven’t seen anything else I like on the Mac yet.