在C#中发送邮件的方式有2种，一种是使用webmail方式进行发送，另外一种就是采用netmail发送的方式，在采用这2种方式发送邮件时，如果采用公用的邮件服务器（如126邮件服务器，Sina的邮件服务器）都是需要授权认证才能够发送，如果是采用Gmail的话，还会有每天发送邮件的数量等限制。这2种方式是经过我测试通过了的代码，只需要将邮件的用户名和密码修改成自己的即可，同时也可以修改邮件服务器，改成自己配置的邮件服务器。
/// <summary>
/// 发送Email(带验证，采用微软新推荐的方式)
/// </summary>
/// <param>收件Email</param>
/// <param>抄送Email</param>
/// <param>标题</param>
/// <param>内容</param>
/// <param>邮箱验证帐号（与web.config里配置的帐号要一样）</param>
/// <param>发信人邮箱，要与UserName对应</param>
/// <param>错误消息</param>
/// <returns></returns>
public static bool WebSendEmail(string strTo, string strCc, string strSubject, string strBody, ref string strErrorMsg)
{
System.Web.Mail.MailMessage message = new System.Web.Mail.MailMessage();
System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(@"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");
bool bState = false;
string strSMTPServer = "";
try
{
strSMTPServer = Convert.ToString(System.Configuration.ConfigurationManager.AppSettings["SMTP"]);
strSMTPServer = strSMTPServer == "" ? "localhost" : strSMTPServer;
string strFromAddr = Convert.ToString(System.Configuration.ConfigurationManager.AppSettings["FromAddress"]);
if (reg.IsMatch(strFromAddr))
{
message.From = strFromAddr;
}
else
{
throw new Exception("The Email Address is wrong,Please reset the Email Address in the web.config file !");
}
string strTemp = "";
foreach (string str in strTo.Split(';'))
{
if (reg.IsMatch(str))
if (!strTemp.Contains(str))
strTemp += str + ";";
}
message.Cc = "";
foreach (string str in strCc.Split(';'))
{
if (reg.IsMatch(str))
if (!message.Cc.Contains(str))
message.Cc += str + ";";
}
message.Subject = strSubject;
message.BodyFormat = System.Web.Mail.MailFormat.Html;
message.Body ="<html><body>UtilMailMessage001"+ strBody+"- success</body></html>" ;
//下面这块是加载附件的方法
MailAttachment attachment1 =new MailAttachment(@"d:\My Documents\test1.doc");
MailAttachment attachment2 =new MailAttachment("d:\\Documents\\test2.doc");
message.Attachments.Add(attachment1);
message.Attachments.Add(attachment2);
message.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true");
message.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1");