Potential work around for the email live tile issue of unread counts....

[peashooter14]

Ok, let me know if this works for you. I pin various email accounts to my start screen, well one of the updates the live tile correctly and the other doesn't. So I began trying to find the differences (gmail versus yahoo...). I think the issue is a common developer bug where they don't handle lists correctly. Yahoo was my first listed email in Manage Accounts...and it DID NOT WORK. I deleted it and added it back in to where it is at the bottom and my Windows Hotmail account (which I don't use for email) is at the top of the list.

Now both my gmail and yahoo live tiles appear to work.

See if it works for you.

 

[Player Piano]

Thank you. I will give it a try. This is getting ridiculous with this broken live tile for email. They worked perfect before the last update.

 

[snakebitten]

I might add that I did one other thing to get my separate tiles to behave.
I deleted all the Start Menu Tiles for my 3 mail accounts when they were not behaving properly.
I then opened the Outlook App from the "unpinned" App launcher and went to each account, one at a time. I would "pin to start" just one account. Then close the Outlook App and remove it from the task manager to make SURE it was closed before I would move on to pinning the next account.

I too suspect there is a glitch similar to the OP suggestion, but I don't know enough to be sure.

By coincidence, I MAY have created my new pinned tiles for each account in the same order they are listed in "settings", just as the OP suggests. But I can't be sure of that either.