Symptom: internal access is working properly, but accessing with Outlook from remote locations is showing an error that autodiscover.yourdomain.com is not part of the SSL certificate.
Solution:
Don't use a single domain certificate, but a wildcard or mutli-domain certificate that not only includes "mail.company.com" but also "autodiscover.company.com".
If you have already ordered a single domain certificate, you can use the 14 days money-back-guarantee and replace it with the proper one.
Multi-Domain certificate:
As with a single domain certificate, create the CSR for "mail.company.com". When placing the CSR inside "My InterSSL", add "autodiscover.company.com" as a SAN Slot.
Wildcard certificate:
Simply create a CSR for *.company.com. The autodiscover. domain will automatically be covered by the wildcard certificate.
White Paper: Understanding the Exchange 2010 Autodiscover Service
https://technet.microsoft.com/en-us/library/jj591328(v=exchg.141).aspx
