smtpClient发邮件错误：不允许使用邮箱名称。 服务器响应为: You are not authorized to send mail, authentication is required
使用smtpClient发送邮件时，经常跑出难以明白的错误。其实主要都和我们申请的免费邮箱有关系。有些邮箱不支持，比如163的以前申请的帐号可以用，新注册的帐号是发不了的。
/**//// <summary>
/// 功能：发送邮件,返回字符串：“发送成功”否则返回错误代码。 /// 创建：2007-08-23 /// </summary> /// <param name="MailTo">MailTo为收信人地址</param> /// <param name="Subject">Subject为标题</param> /// <param name="Body">Body为信件内容</param> /// <param name="BodyFormat">BodyFormat为信件内容格式:0为Text,1为Html</param> /// <param name="Priority">Priority为优先级:0为低,1为中,2为高</param>
/// <param name="Attachments">Attachment为附件,为null则不发送</param>
public static string SendMail(System.Collections.ArrayList MailTo, string Subject, string Body, int BodyFormat, int Priority, string Attachments) 
{ string result; SmtpClient mail = new SmtpClient(); //发送方式 mail.DeliveryMethod = SmtpDeliveryMethod.Network; //smtp服务器 mail.Host = "smtp.sina.com"; //用户名凭证 mail.Credentials = new System.Net.NetworkCredential("mail_user_name", "mail_user_password"); //邮件信息 MailMessage message = new MailMessage(); //发件人 message.From = new MailAddress("mail_user_name@sina.com"); //收件人 foreach (object item in MailTo)
{ message.To.Add(item.ToString());
} //主题 message.Subject = Subject; //内容 message.Body = Body; //正文编码 message.BodyEncoding = System.Text.Encoding.UTF8; //设置为HTML格式 message.IsBodyHtml = true; //优先级 message.Priority = MailPriority.High; try { mail.Send(message); result = "发送成功"; return result; } catch (Exception e) { result = e.ToString(); } return result; }
不同的邮箱，要改的部分主要是“上面代码中高亮的部分”，有些邮箱地址是要加后缀 “@xxx.com”，而有些邮箱只要用户名就好了 .
附带以前2003版的：
/**//// <summary> /// 发送邮件 /// </summary> /// <param name="Sender">发件人邮箱地址</param> /// <param name="Receiver">收件人邮箱地址</param> /// <param name="Title">邮件标题</param> /// <param name="Content">邮件内容</param> /// <param name="SmtpServer">邮箱服务器名称</param> /// <param name="Validate">服务器是否需要验证</param> /// <param name="UserName">验证用户名</param> /// <param name="Password">验证密码</param> /// <returns>结果</returns> public string SendMail(string from,string to,string title,string body,string enclosure, string smtpServer,bool validate,string userName,string password) { MailMessage mail = new MailMessage();//实例化MailMessage mail.From = from; //邮件发件人 mail.To = to;//邮件收件人 mail.Subject = title;//邮件标题 mail.Body = body; //邮件内容 mail.BodyFormat = MailFormat.Html; //邮件文本格式 mail.Priority = MailPriority.Normal;//邮件发送级别 if(enclosure != "") { //添加附件 MailAttachment ma = new MailAttachment(enclosure); mail.Attachments.Add(ma); } //邮件服务器是否需要验证 if(validate) { if(userName != "" && password != "") { mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", userName); mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", password); } else { return "缺少验证用户名和密码"; } } try { SmtpMail.SmtpServer = smtpServer;//设置邮件服务器 //发送邮件 SmtpMail.Send(mail); return "邮件发送成功！"; } catch { return "邮件发送失败！"; } }
来源：http://www.cnblogs.com/oiea/archive/2007/11/06/951234.html
