Feb 13, 2015 - IMAP, Exchange, ActiveSync, CalDAV, CardDAV: Each one syncs mail. With a GoDaddy domain, some ISP's, and some older web hosts). Desktop clients I'm aware of that support EWS include Outlook for Mac 2014, Outlook for Mac 2011. Provided by Exchange Server 2007 and later, and Office 365. Outlook for Mac 2011: Set up email. Launch Outlook. Click Tools, and then Accounts. In the Startup Wizard, click Next. If the Startup Wizard doesn't automatically display, click +, and then select Exchange. Enter your email address and password. Select Configure automatically, and then click Add Account.
Couple of things to check:
Is Autodiscover setup and working for this domain?
Is EWS setup and working for this domain?
If I am remembering rightly Outlook 2011 for Mac is totally different to normal Outlook as it will use Exchange Web Services to connect to the mailbox and this is reliant on Autodiscover so if either of these aren't setup and working fully they could be part of the issue.
It may be worth running through the Autodiscover and EWS tests here to verify everything is ok: https://testconnectivity.microsoft.com/
To set up your email address on your Outlook 2011 for Mac, you'll need your Office 365 email address and password. If you have a Business Premium or Premium Security email plan you can download the most recent version of Outlook for Mac.
You can watch a short video of this task farther down the page.
Launch Outlook.
On the Tools menu, click Accounts. If this is the first account you're adding, under Add an Account select Exchange Account. If you already have an email address in Outlook, in Accounts click Exchange Account.
On the Enter your Exchange account information page, type your email address.
Under Authentication, confirm that User name and password is slected. Then enter your Office 365 email address as your user name and enter your email password.
Confirm that Configure automatically is selected and click Add Account. Outlook will perform an online search to find your email server settings. In the dialog box that asks if you want to allow the server to configure your settings, select the Always use my response for this server check box, and then click Allow.
If Outlook is successful and adds your email address, you'll see it in the Accounts section. If Outlook can't add your email address, you may be asked to enter your Incoming and Outgoing server info (POP/IMAP).