Autodiscover issue Exchange 2013

I am using SBS Essentials 2012R2  with an on premise Exchange 2013 server.
Outbound and in bound mail work fine.  I using internally and externally  to get to email.
My problem is that  autodiscover does not work externally.  
I get the following error whole testing

"Validating the certificate name, Certificate name mismatch".
can anybody tel what I am doing wrong.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Will SzymkowskiSenior Solution ArchitectCommented:
What DNS names do you have configured on your SSL UCC cert? You should have the following... (if you do not have this on your cert, you are required to setup external SRV recrods on your external DNS for this).

You also need to make sure that you configure this on your 2013 CAS server.
Set-ClientAccessServer -AutoDiscoverServiceInternalUri

Open in new window

thombieAuthor Commented:
my Godday cert is  the internal users canconnect  vi internally.  I will make sure is in place
Will SzymkowskiSenior Solution ArchitectCommented:
Yes you will need to add the to the UCC cert as well. If not you need to use a SRV External DNS records for autodiscover to work. Also making sure that you have configured in CAS server as well as i have illustrated in my first post.

10 Tips to Protect Your Business from Ransomware

Did you know that ransomware is the most widespread, destructive malware in the world today? It accounts for 39% of all security breaches, with ransomware gangsters projected to make $11.5B in profits from online extortion by 2019.

thombieAuthor Commented:
DO I need a seperate cert for  ?
Will SzymkowskiSenior Solution ArchitectCommented:
No you do not. When Exchange you can use a UCC/SAN cert (unified communications cert) which you can add multiple names. You would add and


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
thombieAuthor Commented:
That worked thanks sorry for the delay
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Email Servers

From novice to tech pro — start learning today.