Subject Alternative Names in the certificate purchasing

Hi all,

I have a question regarding the SAN and the domain names that will be included in certificate's SAN. The case is as follows:

Server is Exchange Server 2013. Accepted domains are domain111111.com and domain222222.com.

MX record points to mail.domain111111.com, on the public DNS I nave created CNAME record for Autodiscover

autodiscover.domain111111.com. All users have an email account, which is  set at @domain222222.com.

I need to create new certificate request and I wonder whether to include domain domain222222.com in the SAN or to create the

request only with mail.domain111111.com as a common name and autodiscover.domain111111.com as a SAN.