What User authorization objects needed for connecting to SAP from xMII?

We eneter a SAP user and password for connecting to SAP from xMII to retrieve the metadata of the incoming IDocs.

When I specify a user with SAP_ALL user profiles, the IDocs are received properly in xMII. If I specify a user with privileges to run only certain transactions, IDocs are not received in xMII.

What user authorization objects are needed for this user to connect to SAP from xMII?

Thanks,

Sara