Exchange 2013 homeMTA attribute missing

Hi all,

I noticed if I create a user mailbox on exchange 2013 and check the users properties in ADSI Edit, the homeMTA attribute is missing? Is this normal?
If a user mailbox is create on exchange 2007 I can see the homeMTA attribute. But as soon as I migrate the mailbox over to exchange 2013 it disappears?

Why is there no homeMTA attribute for mailboxes on exchange 2013?

Environment:
Windows Server 2008 SP2 Domain Controller
Exchange 2007 + SP3
Exchange 2013 + CU3

Thank you