If you run Exchange 2013 alongside Outlook 2007 or Outlook 2010 then you may see the following errors when you do a send receive. unknown error 0x8004011 and while transmitting error 0x80040115 for this action the exchange server should be online. The emails and folders in Outlook will still continue to update when you send / receive but you will receive the errors above. This is currently a bug in Exchange 2013 however there are a few things we can do to resolve / work around the problems.
The first thing we can change is the authentication method to auto discover and outlook anywhere. To do this follow the commands below from powershell on your Exchange Server and change the server name to your own.
Set-AutodiscoverVirtualDirectory -Identity 'autodiscover(default Web Site)' -WindowsAuthentication $true -BasicAuthentication $true
Set-OutlookAnywhere -Identity:YourExchange2013CASServer\rpc (Default Web Site) -IISAuthenticationMethods Basic,NTLM
Restart the Outlook client and send and receive to test.
Another time you may see this issue is when you attempt to open multiple mailboxes from Exchange 2013 from your outlook client. Microsoft have gave a workaround of only opening one mailbox at a time.
Finally if all of the above fails you can set the mailbox to be online only instead of using cached mode from the control panel of the Outlook client.