Exchange / outlook client cert error

[wickit]

I know I know not the .local .com certificate error again

But I'm banging my head here.

Cert is using external domain name, and outlook moans as per expected.

But I have imported the cert to all clients and checked its installed in the correct store and it is, yet I still get errors.

any pointers would be nice.

 

I have had this working previously installations no issues, but this is the first time I have used exch 2013

 

Thanks