Outlook Any Where

Hi guys

In my Exchange 2013 SP1 environment I have only one problem :

I CAN NOT connect client outside exchange domain with outlook when ever I tried it gives  me : "Microsoft Exchange in unavailable"

I've configure outlook any where and a private CA for certificate also I add SRV record for autodiscover at my DNS Server

I can only connect them with mailbox GUID

Pleas help me which steps I should go to do this job

I need to connect outlook outside the exchange domain with outlook any where without using GUID :(