How to migrate or transfer Windows Live email to OS X Yosemite, using Postbox

Question

I just got an iMac and it didn't migrate my emails from my Windows PC; only some of them.  I gave up on getting them into Apple Mail, but had Postbox (just Google it to find the download site) on my PC for another email account, so I was able to get Postbox on the Mac to accept emails from Postbox on Windows, which means you'll be using Postbox as your email client on your Mac.  Here's what finally worked, after LOTS of trial and error, which I hope you won't have to repeat:
1. On the Windows 7 PC (? works with XP or Windows 8), rom Windows Live Mail (this was 2011 version), click on the blue square in the upper left corner and select Export email, and then select Email messages.
2. Choose Windows Live Mail for the program, then click Next.
3. Enter the name of folder where you want to export them to and click OK.  I suggest making a New Folder (empty) on Desktop, and name it something to describe the group of email folders you want to transfer.  I have a few groups of email master folders with subfolders, and so did this for each master folder.  If you have only one master folder that contains all your email folders, then you'll only have to do this once. Then click Next.
4. In the next window that appears, select all the email folders within the master folder you want to transfer, then click Next.
5. When it finishes exporting, it will say so, and then click Finish.  This can take many minutes or maybe an hour, depending on how many emails you are transferring. 
6. Open Postbox on the Windows PC (free download for 30-day trial, and only $10 for license, so well worth it), and near the top on the left, highlight “Local Folders.”  Then from the File menu select New and then Subfolder to create an email master folder in Local Folder section of Postbox. Select that folder so it's highlighted.
7.  Select Tools in Postbox, then "Import all messages from a directory," then "also from its subdirectories."  Then click on the master folder you created that contains all the email folders you just exported from Windows Live Mail.  You'll see that there is a subfolder named something (mine says "Live ([name]), and another subfolder within that that is the name of the master folder that just received your export.  Select this subfolder and click OK.  (Within that are the subfolders corresponding to your Windows Live email folders.)
8. Within Postbox, right-click on the email master folder you created in step 6, then select Properties, and put your cursor inside the Location box.  You'll probably have to scroll to the right as it will be a long path.  (Mine is Users/[name]/AppData/Roaming/Postbox/Profiles/[long series of random letters and numbers]/Mail/Local Folders/[master email folder name]).
9. Open Windows Explorer and go to the folder in the Location box, and it will have an “sbd” extension in the folder name.  Open that folder, select all the files in it and copy (ctrl-C) them.
10.  Put an SD card or USB drive in your PC (formatted with exFAT, so the Mac can read it), and create a new folder with the same name as the master email folder.  Paste all the copied files into that folder.
11.  Eject the SD/USB and insert into your Mac.
12. Open Postbox on the Mac (free download, again).
13. If you’ve set up an email account in Postbox, select & highlight that account on the top left, otherwise select Local Folders.  Maybe better to just select Local Folders as to not get into conflicts with your email account, especially if it’s IMAP, but I had problems with POP account, too.
14. From the File menu, select New and then Subfolder, and create a Subfolder with the name of your email master folder.
15.  Highlight your new email master folder and repeat step 14 to create a new subfolder named “test” or something like that, which you’ll later delete.  Then QUIT POSTBOX.
16. Repeat step 8 with your master email folder to find the location of this folder on your Mac, then open Finder and open that folder.  There should be a subfolder there named “test”, which confirms that you’re in the right place.
17. Open another Finder window and select the SD/USB drive and the folder in it with your Windows email folders inside it.  Highlight and copy (command-C) all the files within that folder, which will be named something like your Windows Live email folders, but maybe with random letters and numbers at the end.
18.  Paste all those files into the master email folder in first Finder window.  (This is the actual step of moving all your emails from your Windows PC to your Mac.)
19.  Reopen Postbox, and you should see all your email folders (possibly with the  random endings to their names) within the email master folder you created.  If there are a lot of them, it may take Postbox a while to index them all.
20.  To confirm that all your emails transferred, go back to Windows Live Mail on your Windows PC and right click all the email folders you just transferred, and click on Properties, where it will tell you how many messages are in that folder. Write down the number of messages for each folder you transferred.
21.  On your Mac, select each folder, then highlight all the messages in each folder (select the first, the press Shift and select the last message).  Then right-click on the highlighted messages and then click on Mark and then “Mark all as unread.”  Then a number will appear to the right of the folder telling you the number of unread emails, which should equal the numbers you got from Windows Live email folder properties.
22.  If the numbers aren’t equal, then I’m sorry, and it’s time to try it again or do some trial and error.
I tried many different approaches before arriving at this one, which consistently worked for me over and over.  I hope it saves you all the trial and error time it took me.  This is long and complicated, but not as long as trying a bunch of long and complicated methods that didn’t work.  Now you can use Postbox as your email client on your Mac.  Maybe there's a way to transfer them into Apple Mail, but Postbox is fine for me.

Answer 1

PS:  The Mac folder where Postbox stores it's messages is inside the Library folder inside your User folder.  Normally, the Library folder is invisible.  To make it visible in Finder, I did what it said here: 
http://osxdaily.com/2011/07/22/access-user-library-folder-in-os-x-lion/