C # Send Message exception: The remote certificate is not valid according to the verification process

Today in the Send mail function, start with QQ mailbox and 163 mailbox can send normal, and then use my company's mailbox and SMTP when unexpectedly error.

Exception prompt-----"based on the verification process, the remote certificate is invalid", and then through the query data to resolve the problem, on the code:

usinglog4net;usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Net;usingSystem.Net.Mail;usingSystem.Net.Security;usingSystem.Security.Cryptography.X509Certificates;usingSystem.Text;namespacebll{ Public classEmailhandle {Private string_servicetype ="SMTP"; Private string_host; /// <summary>        ///Sender's Mailbox/// </summary>         Public stringfrom {Get;Set; } /// <summary>        ///Recipient Mailbox List/// </summary>         Publiclist<string> to {Get;Set; } /// <summary>        ///cc Mailbox List/// </summary>         Public string[] Cc {Get;Set; } /// <summary>        ///Secret Reader Mailbox list/// </summary>         Public string[] BCC {Get;Set; } /// <summary>        ///Message Subject/// </summary>         Public stringSubject {Get;Set; } /// <summary>        ///Message Content/// </summary>         Public stringBody {Get;Set; } /// <summary>        ///whether it is in HTML format/// </summary>         Public BOOLisbodyhtml {Get;Set; } /// <summary>        ///List of attachments/// </summary>         Public string[] Attachments {Get;Set; } /// <summary>        ///Mailbox Service Type (Pop3,smtp,imap,mail, etc.), default to SMTP/// </summary>         Public stringservicetype {Get{return_servicetype;} Set{_servicetype =value;} }        /// <summary>        ///Mailbox server, which is a mailbox server based on servicetype and sender if no mailbox server is defined/// </summary>         Public stringHost {Get{return_host;} Set{_host =value;} }        /// <summary>        ///email account (default to Sender's email account)/// </summary>         Public stringUserName {Get;Set; } /// <summary>        ///mailbox Password (default to sender's mailbox password), default format GB2312/// </summary>         Public stringPassword {Get;Set; } /// <summary>        ///Mailbox Priority/// </summary>         PublicMailpriority mailpriority {Get;Set; } /// <summary>        ///message body encoding format/// </summary>         PublicEncoding Encoding {Get;Set; } /// <summary>        ///constructing parameters, sending messages, using method notes: Calling in public methods/// </summary>         Public intSend () {varMailMessage =NewMailMessage (); //read to recipient mailbox List            Try            {                if( This. To! =NULL&& This. To.count >0)                {                    foreach(stringToinch  This. To) {if(string. IsNullOrEmpty (To))Continue; MAILMESSAGE.TO.ADD (NewMailAddress (to.                    Trim ())); }                }                //read cc cc email address                if( This. Cc! =NULL&& This. Cc.length >0)                {                    foreach(varCcinch  This. CC) {if(string. IsNullOrEmpty (CC))Continue; MAILMESSAGE.CC.ADD (Newmailaddress (CC.                    Trim ())); }                }                //reading attachments mail attachments                if( This. Attachments! =NULL&& This. Attachments.length >0)                {                    foreach(varAttachmentinch  This. Attachments) {if(string. IsNullOrEmpty (Attachment))Continue; MAILMESSAGE.ATTACHMENTS.ADD (NewAttachment (Attachment)); }                }                //read the BCC secret copy address.                if( This. BCC! =NULL&& This. Bcc.length >0)                {                    foreach(varBccinch  This. BCC) {if(string. IsNullOrEmpty (BCC))Continue; MAILMESSAGE.BCC.ADD (NewMailAddress (BCC.                    Trim ())); }                }                //read from sender addressMailmessage.from =NewMailAddress ( This.                from); //message HeaderEncoding Encoding = encoding.getencoding ("GB2312"); Mailmessage.subject= This.                Subject; //whether the message body is in HTML formatmailmessage.isbodyhtml = This.                isbodyhtml; //message bodyMailmessage.body = This.                Body; Mailmessage.bodyencoding= This.                Encoding; //Message PriorityMailmessage.priority = This.                mailpriority; //Send Message Code implementation                varSmtpClient =NewSmtpClient {Host= This. Host, Enablessl=true, Credentials=NewNetworkCredential ( This. UserName, This. Password)};//add this paragraph before using the company mailbox to send an error: According to the verification process, the remote certificate is invalid//add and then solve the problemServicepointmanager.servercertificatevalidationcallback =Delegate(Object obj, X509Certificate certificate, X509chain chain, sslpolicyerrors errors) {return true; }; //Certificationssmtpclient.send (MailMessage); return 1; }            Catch(Exception ex) {varLoger = Logmanager.getlogger (typeof(Emailhandle)); Loger. Info (string. Format ("Send mail exception, email address: {0}", This. to[0]), ex); return-1; }        }    }}

C # Send Message exception: The remote certificate is not valid according to the verification process