Sync servicenow with active roles cannot get certain attributes

Good Morning.

I am new to the forum and has been working for some time now in Active Roles although without more education that the little information that i can find in the web.

We are trying to automatize certain tasks by synchronizing Servicenow and Active Roles.

We are stuck in the add / remove members from groups. 

For this task, I have created a connection between ARS and Servicenow (using the servicenow connector) and now I am trying to create a Sync Workflow.

Currently, one single step for getting from Servicenow, the content of sys_user_grmember.user.email, transform it to Distinguished name (with a powershell script) and put the info in the Members attribute in ARS.

I can retrieve the neccessary info from the mentioned table in Servicenow, by creating a reference object rule however, I cannot save that to Members as it requires the DN 

My problem is that, when I try to get the same info from Servicenow by using a powershell script, I cannot get anything

I have tried with 

$strValue = $commonParameters.CommonVars.SourceObject.Attributes["sys_user_grmember.email"].Values  (tried with sys_user_grmember, sys_user_grmemeber.sys_user.email.......)

and also

$strValue = $srcObj["sys_user_grmember.email"]

It always comes empty.

Any idea on how can I retrieve the email address of the members of a group from Servicenow?

Best regards