Niche iPhone (ios6?) e-mail problem - can't delete

Question

Hi there,
I was lucky enough to get an iphone 5 on the release day.  I connected my iPhone 5 account with my work e-mail (using exchange) and with other pop e-mail accounts that I have.  Push is working great on my work e-mail account, however, I seem to be having an e-mail deletion problem.  Here is what happened:
I received a calendar invite from a co-worker in e-mail format.  I accepted the invite through outlook on my computer (when you accept it, it auto-deletes the invite e-mail from your inbox and replies with an acceptance notice).  So now, my work inbox is empty.  However, on my iphone, it still shows the invite in the inbox.  When I attempt to delete the e-mail from my iphone, it says that the message cannot be moved or deleted, so it just stays there.  The only way to get rid of the e-mail is to delete that mail account, and then re-add it to my phone.
This also happened on a separate pop-connected e-mail address.  I deleted an e-mail through a webmail interface, the iphone wouldn't see that the e-mail was deleted (even after attempting to sync multiple times) and when attempting to delete it through the Mail app, I received a message stating that the e-mail can't be deleted or moved.
Anyone else having this problem, any suggestions?
Thanks for the help.

Answer 1

If your device is signed into an old iCloud ID, and if it is an earlier version of your current ID*, do the following:
Make sure you are signed into iMessage and FaceTime with your current ID.  If they are signed into the old ID, go to Settings>Messages>Send & Receive and Settings>FaceTime, tap the ID, sign out, then sign back in with your current ID.
Then temporarily recreate the old ID by going to https://appleid.apple.com, click Manage my Apple ID and sign in with your current iCloud ID.  Click edit next to the primary email account, change it back to your old email address and save the change.  (You should not have to verify the old email account so it doesn’t matter if you no longer have access to it.)  Now go to Settings>iCloud, turn off Find My iDevice and enter your current password when prompted (even though it prompts you for the password for your old ID).  Then go to Settings>iCloud, tap Sign Out (or Delete Account if you are not running iOS 8) and choose Delete from My iDevice when prompted (your iCloud data will still be in iCloud).  Next, go back to https://appleid.apple.com and change your primary email address back to the way it was.  Now you can go to Settings>iCloud and sign back in with your current iCloud ID and password (your data will download back to your device).
* If that's not the case, you'll have to contact the Apple account security team and ask for assistance resetting the password for the old ID: Apple ID: Contacting Apple for help with Apple ID account security.  You'll have to be able to prove your identity to them before they will do this.