System.Net.Mail 发送邮件

   使用System.Net.Mail 发送邮件总是提示“验证失败”，从网上也没找到确切的答案，大概是因为公司使用了代理网关，程序不能直接与邮件服务器建立连接。使用System.Web.Mail没有问题。下面是两种发送邮件的代码。
转自：http://www.cnblogs.com/zhouyu629/archive/2009/12/22/1629933.html
 System.Net.Mail 发送邮件
 static string sendMail(string to, string title, string content)
        {
            string strHost = "xxx.xxx.xxx.x";   //STMP服务器地址
            string strAccount = "post@5liao.cc";       //SMTP服务帐号
            string strPwd = "1122333";       //SMTP服务密码
            string strFrom = "post@5liao.cc";  //发送方邮件地址



            SmtpClient _smtpClient = new SmtpClient();
            _smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;//指定电子邮件发送方式
            _smtpClient.Host = strHost; ;//指定SMTP服务器
            _smtpClient.Credentials = new System.Net.NetworkCredential(strAccount, strPwd);//用户名和密码

            MailMessage _mailMessage = new MailMessage(strFrom, to);
            _mailMessage.Subject = title;//主题
            _mailMessage.Body = content;//内容
            _mailMessage.BodyEncoding = System.Text.Encoding.UTF8;//正文编码
            _mailMessage.IsBodyHtml = true;//设置为HTML格式
            _mailMessage.Priority = MailPriority.High;//优先级

            try
            {
                _smtpClient.Send(_mailMessage);
                return "发送成功";
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }

 System.Web.Mail 发送邮件(winform或console程序需要对System.Web进行引用)
 static string sendMail(string to,string title,string content)
        {
            System.Web.Mail.MailMessage _mailMessage = new System.Web.Mail.MailMessage();
            _mailMessage.Body = content;
            _mailMessage.From = "post@5liao.cc";
            _mailMessage.Subject = title;
            _mailMessage.To = to;
            _mailMessage.BodyEncoding = System.Text.Encoding.UTF8;
            _mailMessage.BodyFormat = MailFormat.Html;
            _mailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", 1);
            _mailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "post@5liao.cc");
            _mailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "******"); 
            System.Web.Mail.SmtpMail.SmtpServer = "XXx.xxx.xxx.x"; 
            try
            {
                System.Web.Mail.SmtpMail.Send(_mailMessage);
                return "发送成功";
            }
            catch(Exception ex)
            {
                return ex.Message;
            }
        }

另一篇有附件的用法，转自：http://www.cnblogs.com/aminta/archive/2008/11/08/1281357.html
主要是用到了System.Web.Mail命名空间,用到了此空间的三个类,分别是:


●MailMessage类,用于构造电子邮件
●MailAttachment类,用于构造电子邮件附件
●SmtpMail类,用于发送电子邮件及其附件
1、MailMessage类构造电子邮件
此类主要有以下属性和方法
★From 发件人的地址
★To 以分号分隔的收件人的地址列表
★Cc 以分号隔开的抄送的收件人的邮件地址列表
★Subject 电子邮件的主题
★Body 电子邮件的正文
★BodyFormat 电子邮件的正文内容类型，由MailFormat枚举值指定，MailFormat.Text或MailFormat.Html
★Attachments 电子邮件附件集合
★Priority 电子邮件的优先级，由MailPriority枚举值指定，可以是MailPriority.Low ,MailPriority.Normal或MailPriority.High三者之一
2、Attachment用来构造电子邮件附件.用此类构造了电子邮件附件然后添加到MailMessage对象的Attachments集合即可
3、使用SmtpMail类发送电子邮件,可以通过系统本身的SMTP邮件服务或者其它SMTP服务器来发送,发送电子邮件首先需要设置SmtpMail类的SmtpServer属性,然后使用Send方法发送就可以了
下面做个简单的邮件发送例子:


using System.Web.Mail;

/// <summary>
/// 给业务面试人发送面试通知邮件
/// </summary>
/// <returns>true/false</returns>

//发送邮件
bool sendmailbusi()
{
System.Web.Mail.MailMessage mail = new System.Web.Mail.MailMessage();
mail.From = "aminta@sohu.com";
mail.To = "aminta@sohu.com";
mail.Subject = "测试邮件";
mail.Body = "这是一封测试邮件";
mail.BodyFormat = System.Web.Mail.MailFormat.Html;
mail.BodyEncoding = System.Text.Encoding.UTF8; //邮件内容编码

//构造添加附件（可以发多个附件给多个收件人）
System.Web.Mail.MailAttachment mailAttach_1 = new System.Web.Mail.MailAttachment(@"E:\上岗考核表-入职.doc");
System.Web.Mail.MailAttachment mailAttach_2 = new System.Web.Mail.MailAttachment(@"E:\填表说明.doc");
System.Web.Mail.MailAttachment mailAttach_3 = new System.Web.Mail.MailAttachment(@"E:\上岗考核表-转正.doc");
mail.Attachments.Add (mailAttach_1);
mail.Attachments.Add(mailAttach_2);
mail.Attachments.Add(mailAttach_3);

System.Web.Mail.SmtpMail.SmtpServer = "smtp.sohu.com"; // 发送邮件服务器端口 
//验证

mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //是否需要验证，一般是要的 
mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "aminta"); //自己邮箱的用户名 
mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "123456"); //自己邮箱的密码

try
{
System.Web.Mail.SmtpMail.Send(mail);
return true;
}
catch
{
return false;
}
}

// 05的应该是：

例如： 
//发送邮件（含附件） 
bool sendmail(string mailto,string mailfrom,string content,string loginname,string psd) 
{ 
System.NET.Mail.MailMessage mail = new 
System.Net.Mail.MailMessage(); 
mail.From = new System.Net.Mail.MailAddress(mailfrom.Trim()); 
mail.To.Add(mailto.Trim()); 
mail.Subject = "xx公司面试通知函"; 
mail.IsBodyHtml = true; 
mail.BodyEncoding = System.Text.Encoding.UTF8; 
//附件 
string strFilePath = @"E:\logo.jpg"; 
System.Net.Mail.Attachment attachment1 = new System.Net.Mail.Attachment(strFilePath);//添加附件 
attachment1.Name = System.IO.Path.GetFileName(strFilePath); 
attachment1.NameEncoding = System.Text.Encoding.GetEncoding("gb2312"); 
attachment1.TransferEncoding = System.Net.Mime.TransferEncoding.Base64; 
attachment1.ContentDisposition.Inline = true; 
attachment1.ContentDisposition.DispositionType = System.Net.Mime.DispositionTypeNames.Inline; 
string cid = attachment1.ContentId;//关键性的地方，这里得到一个id数值 
mail.Attachments.Add(attachment1); 
//邮件正文 
mail.Body ="<table width='100%'><tr><td><img src ='cid:"+cid+"'/></td></tr>" +content.Trim();

System.Net.Mail.SmtpClient server = new System.Net.Mail.SmtpClient("mail.xxxx.xxx"); //之前一不留神把公司域名挂上了，在头儿的提醒下赶紧改了，不然惨了，^0^
server.Credentials = new System.Net.NetworkCredential(loginname.Trim(), psd.Trim()); //用户名和密码

try 
{ 
server.Send(mail);

return true; 
} 
catch 
{ 
return false; 
}

}