Exchange 2007 to Exchange 2013 Cross Forest Migration

I will be Migrating Exchange 2007 to exchange 2013 , it will be a cross forest migration.

Following are the details:

DOMAIN A ( Source Domain)

Exchange 2007 SP3

2 2012 R2 DCS

DOMAIN B (Target Domain)

Exchange 2013 2MBX and 2 CAS servers

4 DCS 2012 R2

I have already created  the two way trust between both the domains. Migrated few test user using ADMT and Password Export

Also the PS Powershell script. It says mailbox Ready to move

I started the remote move request and it gives the following Error:

The call to 'https://exchange.domainA.local/EWS/mrsproxy.svc' failed. Error details: Could not establish trust
relationship for the SSL/TLS secure channel with authority 'exchange.alfahad.local'. --> The underlying connection was
closed: Could not establish trust relationship for the SSL/TLS secure channel. --> The remote certificate is invalid
according to the validation procedure..
    + CategoryInfo          : NotSpecified: (:) [New-MoveRequest], RemoteTransientException
    + FullyQualifiedErrorId : [Server=ETI-PROD-MBX1,RequestId=19f2618d-71c2-4d7b-b6f0-dc127f70a097,TimeStamp=7/10/2016
    7:36:07 AM] [FailureCategory=Cmdlet-RemoteTransientException] 310DD59,Microsoft.Exchange.Management.RecipientTask
  s.NewMoveRequest

MRS Proxy feature is not available in 2007 . I ready articles which says enable MRS PROXY on Exchange 2013 CAS , I tried it but it doesnt work

Also same certificates have been applied on the Exchange servers.

Please help me how to proceed with this further