C# uses Exchange to send emails

using ;
using System;
using ;
using ;
using ;
using ;
using ;

namespace 
{
    /// <summary>
    /// Exchange mail client class    /// </summary>
    public class ExChangeMailClient
    {
        /// <summary>
        /// Exchange service object        /// </summary>
        private static ExchangeService _exchangeService = new ExchangeService(ExchangeVersion.Exchange2010_SP1);
        /// <summary>
        /// Get Inbox        /// </summary>
        /// <param name="userId">Current username</param>        /// <param name="pwd">Password</param>        /// <param name="domain">Domain</param>        /// <param name="pageSize">number of loads at one time</param>        /// <param name="offset">offset</param>        /// &lt;returns&gt;&lt;/returns&gt;
        public static List&lt;Email&gt; GetInbox(string userId, string pwd, string domain, int pageSize, int offset)
        {
            try
            {
                if ((userId) || (pwd) || (domain))
                {
                    throw new ArgumentNullException("The current user information is empty, the exchange server cannot be accessed");
                }
                List&lt;Email&gt; lstEmails = new List&lt;Email&gt;();
                _exchangeService.Credentials = new NetworkCredential(userId, pwd, domain);
                _exchangeService.Url = new Uri();
                ItemView view = new ItemView(pageSize, offset);
                FindItemsResults&lt;Item&gt; findResults = _exchangeService.FindItems(, SetFilter(), view);
                foreach (Item item in )
                {
                    ();
 //Convert to EmailMessage to get email details var currentEmail = ()(item); List<string> ccRecipientsEmailLists = new List<string>(); List<string> bccRecipientsEmailLists = new List<string>(); foreach (var cc in ) { (); } foreach (var bcc in ) { (); } (new Email() { ExchangeItemId = , body = , Mail_cc = (";", ()), Mail_bcc = (";", ()), Mail_from = ,  IsRead = , Subject = , CreateOn = });
                }
                return lstEmails;
            }
            catch (Exception ex)
            {

                throw ex;
            }

        }

        /// &lt;summary&gt;
        /// Return the number of unread emails of the user based on the user's email address        /// &lt;/summary&gt;
        /// &lt;param name="user"&gt;&lt;/param&gt;
        /// &lt;returns&gt;&lt;/returns&gt;
        public static int GetUnReadMailCountByUserMailAddress(string userId, string pwd, string domain, string email)
        {
            int unRead = 0;
            try
            {
                _exchangeService.Credentials = new NetworkCredential(userId, pwd, domain);
                _exchangeService.Url = new Uri();
                _exchangeService.ImpersonatedUserId = new (, email);

                unRead = (_exchangeService, ).UnreadCount;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            return unRead;
        }
        /// &lt;summary&gt;
        /// Filter        /// &lt;/summary&gt;
        /// &lt;returns&gt;&lt;/returns&gt;
        private static SearchFilter SetFilter()
        {
            List&lt;SearchFilter&gt; searchFilterCollection = new List&lt;SearchFilter&gt;();
            //(new (, false));
            //(new (, true));
            //Filter today's email            SearchFilter start = new (, (("yyyy-MM-dd 00:00:00")));
            SearchFilter end = new (, (("yyyy-MM-dd 23:59:59")));
            (start);
            (end);
            SearchFilter filter = new (, ());
            return filter;
        }
        /// &lt;summary&gt;
        /// Send email        /// &lt;/summary&gt;
        /// &lt;param name="email"&gt;&lt;/param&gt;
        /// &lt;returns&gt;&lt;/returns&gt;
        public static void SendMail(Email email, string userId, string pwd, string domain)
        {
            try
            {
                _exchangeService.Credentials = new NetworkCredential(userId, pwd, domain);
                _exchangeService.Url = new Uri();
                //Send by                Mailbox mail = new Mailbox(email.Mail_from);
                //Email content                EmailMessage message = new EmailMessage(_exchangeService);
                string[] strTos = email.Mail_to.Split(';');
                //Recipient                foreach (string item in strTos)
                {
                    if (!(item))
                    {
                        (item);
                    }
                }
                //Check the person                foreach (string item in email.Mail_cc.Split(';'))
                {
                    if (!(item))
                    {
                        (item);
                    }

                }
                //Email Title                 = ;
                //Email content                 = new MessageBody();
                //Send and save                ();

            }
            catch (Exception ex)
            {
                throw new Exception("There was an error sending the email," +  + "\r\n" + );
            }
        }
    }
}