MS Outlook Issues after Windows 10 upgrade

I have a clean install of Windows 10 and Office Pro 2013. Initially I could not send any emails from Outlook. I resolved this by running SFC /scannow. However, I am getting constant sync errors and a blue circle when using Outlook with IMAP. The 2 accounts I have added are my Gmail account and my iCloud account, both have the same issues and currently it makes Outlook unusable.

All accounts work fine in EMClient, so the issue appears isolated to Outlook, I also have the same issue on my Dad's PC running Windows 10 and Outlook 2010 (although 2010 doesn't seem quite as bad as 2013). I'm not too bothered, but my Dad is hassling me to fix it as it work on Windows 8 and he seems attached to Outlook after using it for many years!

Has anyone experience these sort of issues and managed to resolve them? Both Office installs are fully updated and all other applications work ok. If I use Outlook with a POP mail account it seems to be ok, but this is not an option given IMAP keeps all devices inline, which is a requirement.

Ok, so I removed my iCloud account and my Gmail account seems to be working as it should. This suggest the issue could be with the iCloud connector.

I added the iCloud mail account with the connector uninstalled and the mail works as expected, folders sync correctly and no blue circle. The only downside here is no calendars or contacts.