string runasUsername = "admin@abc.at";
    string runasPassword = "MyPassword";
        System.Security.SecureString ssRunasPassword = new
        System.Security.SecureString();
        foreach (char x in runasPassword)
        ssRunasPassword.AppendChar(x);
        PSCredential credentials = new PSCredential(runasUsername, ssRunasPassword);
        var connInfo = new WSManConnectionInfo(new
        Uri("http://ex01.abc.at/PowerShell"),
        "http://schemas.microsoft.com/powershell/Microsoft.Exchange", credentials);
        connInfo.AuthenticationMechanism = AuthenticationMechanism.Kerberos;

        var runspace = RunspaceFactory.CreateRunspace(connInfo);

        string script = @"Set-ADServerSettings -ViewEntireForest:$true
        get-mailbox Administrator | format-table";

        runspace.Open();
        var pipeline = runspace.CreatePipeline();

        pipeline.Commands.AddScript(script);
        Collection<PSObject> resultss = pipeline.Invoke();
        string str = "";

        foreach (PSObject psObject in resultss)
        {
        str = str + psObject;
        }
        runspace.Dispose();
        Label1.Text=str;