Exchange 2013/Shared Accounts

I am hosting multiple domain names in my Exchange 2013 environment and require shared mailbox accounts with the same alias, that is

enquiries@domainA.co.uk
enquiries@domainB.co.uk

I have managed to created these shared mailboxes through EAC and all looks good to go.

I can add enquiries@domainA.co.uk to any Outlook clients requiring it using

File-Account Settings-Account-Settings-New-E-mail Address:enquiries@domainA.co.uk-Next-Finish

but when I try to add enquiries@domainB.co.uk I get an error back stating:

An encrypted connection to your mail server is not available.
Click Next to attempt using an unencrypted connection.

I then get the option to configure the shared mailbox manually, but because it is an Exchange account I am unable to proceed.

I suspect that the Autodiscovery process is failing because I do not have autodiscover.domainB.co.uk referenced in my UCC SAN SSL certificate.

Before I go off and rekey my SSL certificate can anyone confirm my thoughts or offer some other solution?

Thank You

Brian