Can't turn on iCloud Mail

Question

After upgrading to Mavericks, I noticed that my Notes were not syncing to iCloud from my iMac (all other devices work fine). I disabled iCloud on my iMac completely and logged back in. After doing so, I was not able to add back my Notes, or iCloud email. This problem persisted for a day, when Notes finally set up
. Mail is still offline. Everything is working fine on all of my other devices, including my MBP running Mavericks. When trying to enable iCloud mail, I get the error: Your iCloud Mail account could not be enabled. I was getting a sililar error for Notes before it finally kicked in. I have logged out and logged back into iCloud a few times, deleting all iCloud content from my Mac in the process. Everything comes back as it should when I log back in, save for Email.
Aside from disabling and enabling iCloud, I have repaired permissions, run disk utility from the recovery partition, and booted to safe mode. No dice.
Does anyone have a suggestion?

Answer 1

Fixed it.
Found another post with a similar problem - don't want to take credit for someone else's solution!
this is what I did:
The problem was caused by dodgy entries in the accounts.plist file in my User Library folder. It appears that either when I upgraded to Mavericks this file gained many thousands of duplicate entries, or maybe these entries were in there before but previously the OSX/Mail combination was more tolerant. When I removed these the problem with Mail disappeared. Here’s what I did….
1> Make the user Library folder visible - in Mavericks this is a lot easier than Lion/Mountain Lion. Simply open up your user directory in Finder, select menu View>Show View Options, and select “Show Library Folder”
2> Navigate through username>Library>Mail>V2>MailData and select the Accounts.plist file. If this file is multiple megabytes (mine was 40+mb) then this is likely the cause of your problem (once sorted mine ended up at 19k in size!)
3> To be safe, make a copy of this file (I placed the copy on my desktop).
4> Using your chosen text editor (I used Text Wrangler but I’m sure TextEdit would work just fine) open the Accounts.plist in the MailData folder (not your backup copy) and take a look. If it’s the same as me you will find hundreds and hundreds of entries for the same mailbox repeated in there. Mine was an old MSN mailbox that I never use any more (I’ve seen in other forums that other Hotmail type accounts also seem to be the culprits in this context). There will likely be two lots of repeated data, one in the XML “DeliveryAccounts” <array> section, and one lot in the “MailAccounts” <array> section.
5> Delete (keeping in mind the need to select the XML sections correctly from <dict> to </dict> completely) all those extra entries that you found, keeping the mail accounts you do need, in the XML and save the file.
6> Mail should open up nice and fast again and not eat your system
7> If this did not work, and causes problems because of over eager deleting in <5> you can replace your broken Accounts.plist file with your backup and try again.