autodiscover will be all you need if
mail.yourdomain.com is your Exchange FQDN.
See the Exchange 2013 Digital Certificates and SSL documentation which states:
Best practice: Use the Exchange certificate wizard to request certificates*
There are many services in Exchange that use certificates. A common
error when requesting certificates is to make the request without
including the correct set of service names. The certificate wizard in
the Exchange Administration Center will help you include the correct
list of names in the certificate request. The wizard lets you specify
which services the certificate has to work with and, based on the
services selected, includes the names that you must have in the
certificate so that it can be used with those services. Run the
certificate wizard when you've deployed your initial set of Exchange
2013 servers and determined which host names to use for the different
services for your deployment. Ideally you'll only have to run the
certificate wizard one time for each Active Directory site where you
Instead of worrying about forgetting a host name in the SAN list of
the certificate that you purchase, you can use a certification
authority that offers, at no charge, a grace period during which you
can return a certificate and request the same new certificate with a
few additional host names.
It further goes on to state:
Best practice: Use as few host names as possible
In addition to using as few certificates as possible, you should also
use as few host names as possible. This practice can save money. Many
certificate providers charge a fee based on the number of host names
you add to your certificate.
The most important step you can take to reduce the number of host
names that you must have and, therefore, the complexity of your
certificate management, is not to include individual server host names
in your certificate's subject alternative names.
The host names you must include in your Exchange certificates are the
host names used by client applications to connect to Exchange. The
following is a list of typical host names that would be required for a
company named Contoso:
Mail.contoso.com This host name covers most connections to Exchange, including Microsoft Outlook, Outlook Web App, Outlook
Anywhere, the Offline Address Book, Exchange Web Services, POP3,
IMAP4, SMTP, Exchange Control Panel, and ActiveSync.
Autodiscover.contoso.com This host name is used by clients that support Autodiscover, including Microsoft Office Outlook 2007 and
later versions, Exchange ActiveSync, and Exchange Web Services
Legacy.contoso.com This host name is required in a coexistence scenario with Exchange 2007 and Exchange 2013. If you'll have clients
with mailboxes on Exchange 2007 and Exchange 2013, configuring a
legacy host name prevents your users from having to learn a second URL
during the upgrade process.