用于管理Exchange Server的WDSL web服务

我创建了一个web服务，它应该允许向Exchange Server Powershell传递命令。当我通过使用VS (localhost)在机器上运行它来测试它时，一切都正常。但是，当我尝试从其他机器上使用此服务时。I get Access Denied Error.

这是服务:

using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Collections.ObjectModel;
using System.Management.Automation;
using System.Management.Automation.Remoting;
using System.Management.Automation.Runspaces;
using System.Configuration;
using Microsoft.Exchange.WebServices.Data;
namespace pshell
{
    [WebService(Namespace = "http://some1.domain.int/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    public class PowerShellService : System.Web.Services.WebService
    {
        private bool Authenticate(string u, string p)
        {
            if ((u == "xxxxxx") && (p == "xxxxxxx"))
                return true;
            else
                return false;
        }
        private int SecurityLevel(string u)
        {
            if (u == "xxxxx")
                return 100;
            else
                return 0;
        }
        [WebMethod]
        public string PSCmd(string authuser, string authpass, string cmd, string pars)
        {
            if (!Authenticate(authuser, authpass))
                return "<collection><RESULT status='"ERROR'" message='"Authentication failed!'" /></collection>";
            String Password = System.Configuration.ConfigurationManager.AppSettings["UUPASS"];
            System.Security.SecureString secureString = new System.Security.SecureString();
            foreach (char c in Password)
                secureString.AppendChar(c);
            PSCredential ExchangeCredential = new PSCredential(System.Configuration.ConfigurationManager.AppSettings["UUNAME"], secureString);
            WSManConnectionInfo connectionInfo = new WSManConnectionInfo(new Uri(System.Configuration.ConfigurationManager.AppSettings["UURI"]), "http://schemas.microsoft.com/powershell/Microsoft.Exchange", ExchangeCredential);
            Runspace runspace = RunspaceFactory.CreateRunspace(connectionInfo);
            connectionInfo.AuthenticationMechanism = AuthenticationMechanism.Basic;
            PowerShell powershell = PowerShell.Create();
            PSCommand command = new PSCommand();
            if (cmd.Trim() != "")
            {
                //here we check for security level
                if (SecurityLevel(authuser) >= 100)
                {
                    //admin fully allowed
                    command.AddCommand(cmd);
                }
                else
                {
                    //test for allowed commands
                    if ((SecurityLevel(authuser) < 100) &&
                        (SecurityLevel(authuser) >= 90))
                    {
                        if (cmd.ToLower() == "get-mailbox")
                        {
                            command.AddCommand(cmd);
                        }
                    }
                }
            }
            else
                return "<collection><RESULT status='"ERROR'" message='"Missing command!'" /></collection>";
            if (pars.Trim() != "")
            {
                string[] parameters = pars.Split('|');
                foreach (string item in parameters)
                {
                    String p = item.Substring(0, item.IndexOf("="));
                    String v = item.Substring(item.IndexOf("=") + 1);
                    if (p.Trim().ToLower() == "password")
                    {
                        System.Security.SecureString passString = new System.Security.SecureString();
                        foreach (char c in v)
                            passString.AppendChar(c);
                        command.AddParameter(p, passString);
                    }
                    else if ((v.Trim().ToLower() == "false") ||
                             (v.Trim().ToLower() == "true"))
                    {
                        if (v.Trim().ToLower() == "false")
                            command.AddParameter(p, false);
                        else
                            command.AddParameter(p, true);
                    }
                    else
                    {
                        command.AddParameter(p, v);
                    }
                }
            }
            powershell.Commands = command;
            runspace.Open();
            Pipeline pl = runspace.CreatePipeline();
            powershell.Runspace = runspace;
            Collection<PSObject> results = null;
            string xml = "<collection>";
            try
            {
                results = powershell.Invoke();
                var error = pl.Error.Read() as Collection<ErrorRecord>;
                if (error != null)
                {
                    foreach (ErrorRecord er in error)
                    {
                        xml += "<RESULT status='"ERROR'" type='"pipe'" message='"" + er.ErrorDetails.Message + "'" />";
                    }
                    pl.Stop();
                }
                xml += "<RESULT status='"OK'" />";
            }
            catch(Exception err)
            {
                xml += "<RESULT status='"ERROR'" type='"exception'" codelevel='"1'" message='"" + err.Message + "'" />";
            }
            try
            {
                foreach (PSObject item in results)
                {
                    for (int i = 0; i < item.Properties.Count(); i++)
                    {
                        if (item.Properties.ElementAt(i).MemberType == PSMemberTypes.Property)
                        {
                            xml += "<" + item.Properties.ElementAt(i).Name + ">" +
                                   item.Properties.ElementAt(i).Value +
                                   "</" + item.Properties.ElementAt(i).Name + ">";
                        }
                    }
                }
            } 
            catch(Exception err)
            {
                xml += "<RESULT status='"ERROR'" type='"exception'" codelevel='"2'" message='"" + err.Message + "'" />";
            }
            xml += "</collection>";
            return xml;
        }
    }
}

这是我要用来发送命令的PHP代码:

$ini = ini_set("soap.wsdl_cache_enabled","0");
$params = array('authuser' => 'xxxx', 
                'authpass' => 'xxxx', 
                'cmd' => 'get-mailbox', 
                'pars' => '');
$client = new SoapClient("http://web.domain.com/pshell/callpshell.asmx?WSDL", array('soap_version' => SOAP_1_2));
$response = $client->PSCmd($params)->PSCmdResult;
print $response;

，这是我收到的错误信息:

连接到远程服务器some1.domain.int失败，错误信息如下:Access is denied。有关详细信息，请参阅about_Remote_Troubleshooting帮助主题。

我已经在Exchange服务器上启用了远程访问，并且我做了所有远程故障排除建议。

有什么建议吗?