Mail folder file structure confusion

david,

Thanks for clearing up my confusion on the file system storage level of dual folders. I actually already knew that 'whites' may contain other 'whites' -- that part of my post was just badly edited. Duh.

However, I'm still at a loss to identify 'whatever reason' created the empty Pxxxx file. (See my second reply below.)

Ernie,

My remaining problem is I have never used an earlier version of Mail, nor did I do any editing or moving of folders in Finder, or anything else I'm aware of that explains why the folder appeared. On this iMac, I have not disturbed the file structure in Finder in any way, nor have I imported anything into Mail.

The whole white, "folder only" mailbox concept remains confusing to me. I can't figure out why I have one of these that I did not create with the "slash" method, but as a simple, root level "On my Mac" folder. I created new child folders within it before putting any individual messages in it. Somewhere along the line it became white, preventing me from adding messages directly to it, which is annoying.

Any clues on what I'm missing in my understanding here?

In Mail 2.x, you must remember that moving things
around in the Finder, will cause the Envelope Index
(the only index, now) to lose contact with the
messages.

To my knowledge, I have not moved any ~/Library/Mail/ files/folders around in Finder on this iMac, only examined the contents. Please don't be confused by my other recently posted Mail topics -- on this iMac G5, I have been very careful about this, up to & including making copies of the entire ~/Library/Mail/ folder to examine, rather than the "real" version Mail.app uses.

More info, please, and feel free to email me any
screenshots. I will try to examine, even though I
presently have access remotely with my iBook, and not
my main computer.

A very kind offer! For reasons of privacy & security, would edited text files of the folder structure do instead? I'm not comfortable with sending screen shots because of some of the info that would reveal.

BTW, how do you know when it was created?

Both by creation/modification dates & by comparison to archived copies & a clone of the drive.

I understand that the Pxxx folder could have been created by moving folders around from within Mail. My confusion now is how a once-blue mailbox can become a white one if I only manipulate mailboxes from within Mail.

Beware that Mail doesn't provide full support
to handle these things properly from within
Mail itself, and it has some bugs that may
lead to data loss...

That's why I want to make sure I understand what it does & doesn't support, & what to be wary of doing inadvertently!

I believe I've already answered what could
cause this under "normal" operation.

I guess I missed something. I have never tried to delete the folder that became white or any of its contents, nor is it a dual folder with both .mbox & non .mbox versions in the file structure. It has not been renamed & has a unique but normal all text one. Here is how it was created & what happened:

I created the folder at the root level as an "On my Mac" mailbox, with the popup "New Mailbox..." command. It was named normally, with no slash or any punctuation at all, just the text "Web Account info." At this point it was an empty, blue folder. I then created a number of child folders for it, each for account info messages from a different source like isp's, paypal, or whatever. Some were created with the popup menu as its children, others were created at the root level & then dragged into it. All were empty at the time. All were still blue.

Once this was done, I created rules to move inbox messages from the appropriate source into the child folders. I also manually dragged some previously saved messages on my Mac into them. Everything worked fine so I quit Mail. To the best of my knowledge, the parent mailbox remained blue until some subsequent launch of Mail, when I noticed it had turned white.

All of this was done from within Mail; no folder manipulation of any sort was done with Finder or Terminal.

I apparently "did something I'm not aware of" to cause this, but I have no idea what kind of thing that might have been -- from what you folks have told me, I would have had to have a dual mailbox at some point or messed with the files in Finder to make this possible, but I am reasonably sure neither condition obtained.

Or maybe you were hit by one of the bugs I'm talking
about...

Possibly so. I just wish Mail had better documentation about its normal, expected behavior, which might help pin such things down. The problem seems to be that it tries to do so much behind the scenes to simplify the user experience that I'm never quite sure what I have done vs. what it has done for me.

One final oddity I just noticed in testing a few things:

I created a regular blue, root level folder named "Test" in Mail. I copied a message into it. (All files/folders are local, not on servers.) At this point it was not a dual mailbox, just a regular one that in the file structure had only a .plist & Messages folder with a single emlx file.

In Mail, I then deleted the mailbox, answering the 'do you want to delete it & its contents' prompt in the affirmative.

Strangely, it left a white "Test" folder in the mailbox list. I could delete that in the same way from Mail, but I have no idea why it 'went white.'