SMTP是一种提供可靠且有效的电子邮件传输的协议。SMTP是建立在FTP文件传输服务上的一种邮件服务，主要用于系统之间的邮件信息传递，并提供有关来信的通知。
以Winform为例：
首先需要引用
using System.Net.Mail;
using System.Net.Mime;
按钮的点击事件
private void button1_Click(object sender, EventArgs e)
{
SendEmail();
} public bool SendEmail()
{
bool bResult = true;
string sResult = string.Empty;
try
{
string strSQL = string.Empty;
DataTable dt = new DataTable();
string TimeNow = string.Empty;
DataTable dtReport = null;
List<string> lsCode = null;
//TimeNow = System.DateTime.Now.AddHours(-2).ToString("yyyy-MM-dd HH:mm:ss");
#region 短缺发料报表
//每天上班8点发送前一天的报表，只发送一次
//if (System.DateTime.Now.Hour.ToString() == "8")
//{
TimeNow = System.DateTime.Now.AddDays(-1).ToString("yyyy-MM-dd");
try
{
string sSubject = string.Empty;
string sTitle = string.Empty;
string sBody = string.Empty;
string BatchCode = string.Empty;
//附件路径
string DicPath = string.Empty;
string attachName = string.Empty;
string attachPath = string.Empty;
string sPath = string.Empty;
string sFile = string.Empty;
//邮件内容
string sContent = "<p>Dear Receiver:</p><p>You have a warning report of picking list, kindly check it.</p><p>System email, please don’t reply directly.</p>";
DataTable dtEmailUser = new DataTable();
#region 发送
strSQL = "select * from v_storage_list where run_status not in('Selected','Enable')";
sSubject = "WO Warning List";
sTitle = "<tr><td style=\"width:10%\" align=\"center\">WO ID</td><td style=\"width:10%\" align=\"center\">BOX_BARCODE</td></tr>";
sBody = "<table border=\"1\" cellspacing=\"0\" cellpadding=\"0\">" + sTitle + sBody + "</table>";
//sjw 20220216 增加内容
sBody = string.Format("{0}{1}", sContent, sBody);
#endregion
string senderServerIp = textBox1.Text; //发件服务器
string mailPort = "25"; //发送邮件所用的端口号（htmp协议默认为25）
string fromMailAddress = "";//发件人可以为空
string subjectInfo = sSubject;
string bodyInfo = sBody;
string mailUsername = string.Empty;//发件箱的用户名（即@符号前面的字符串，例如：[email protected]，用户名为：hello）
string mailPassword = string.Empty; //发件人邮箱密码
string toMailAddress = string.Empty;
toMailAddress = textBox2.Text;
EmailHelper email = new EmailHelper(senderServerIp, toMailAddress, fromMailAddress, subjectInfo, bodyInfo, mailUsername, mailPassword, mailPort, false, false);
email.AddAttachments(attachPath);
bResult = email.Send();
}
catch (Exception ex)
{
bResult = false;
sResult = ex.Message;
}
//}
#endregion
}
catch (Exception ex)
{
bResult = false;
sResult = ex.Message;
}
return bResult;
}添加一个Helper类EmailHelper
public class EmailHelper
{
private MailMessage mMailMessage; //主要处理发送邮件的内容（如：收发人地址、标题、主体、图片等等）
private SmtpClient mSmtpClient; //主要处理用smtp方式发送此邮件的配置信息（如：邮件服务器、发送端口号、验证方式等等）
private int mSenderPort; //发送邮件所用的端口号（htmp协议默认为25）
private string mSenderServerHost; //发件箱的邮件服务器地址（IP形式或字符串形式均可）
private string mSenderPassword; //发件箱的密码
private string mSenderUsername; //发件箱的用户名（即@符号前面的字符串，例如：[email protected]，用户名为：hello）
private bool mEnableSsl; //是否对邮件内容进行socket层加密传输
private bool mEnablePwdAuthentication; //是否对发件人邮箱进行密码验证
///<summary>
/// 构造函数
///</summary>
///<param name="server">发件箱的邮件服务器地址</param>
///<param name="toMail">收件人地址（可以是多个收件人，程序中是以“;"进行区分的）</param>
///<param name="fromMail">发件人地址</param>
///<param name="subject">邮件标题</param>
///<param name="emailBody">邮件内容（可以以html格式进行设计）</param>
///<param name="username">发件箱的用户名（即@符号前面的字符串，例如：[email protected]，用户名为：hello）</param>
///<param name="password">发件人邮箱密码</param>
///<param name="port">发送邮件所用的端口号（htmp协议默认为25）</param>
///<param name="sslEnable">true表示对邮件内容进行socket层加密传输，false表示不加密</param>
///<param name="pwdCheckEnable">true表示对发件人邮箱进行密码验证，false表示不对发件人邮箱进行密码验证</param>
public EmailHelper(string server, string toMail, string fromMail, string subject, string emailBody, string username, string password, string port, bool sslEnable, bool pwdCheckEnable)
{
try
{
mMailMessage = new MailMessage();
mMailMessage.To.Add(toMail);
mMailMessage.From = new MailAddress(fromMail);
mMailMessage.Subject = subject;
mMailMessage.Body = emailBody;
mMailMessage.IsBodyHtml = true;//用网页形式显示内容
mMailMessage.BodyEncoding = System.Text.Encoding.UTF8;
mMailMessage.Priority = MailPriority.Normal;
this.mSenderServerHost = server;
this.mSenderUsername = username;
this.mSenderPassword = password;
this.mSenderPort = Convert.ToInt32(port);
this.mEnableSsl = sslEnable;
this.mEnablePwdAuthentication = pwdCheckEnable;
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
}
///<summary>
/// 添加附件
///</summary>
///<param name="attachmentsPath">附件的路径集合，以分号分隔</param>
public void AddAttachments(string attachmentsPath)
{
try
{
string[] path = attachmentsPath.Split(';'); //以什么符号分隔可以自定义
Attachment data;
ContentDisposition disposition;
for (int i = 0; i < path.Length; i++)
{
data = new Attachment(path[i], MediaTypeNames.Application.Octet);
disposition = data.ContentDisposition;
disposition.CreationDate = System.IO.File.GetCreationTime(path[i]);
disposition.ModificationDate = System.IO.File.GetLastWriteTime(path[i]);
disposition.ReadDate = System.IO.File.GetLastAccessTime(path[i]);
mMailMessage.Attachments.Add(data);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
}
///<summary>
/// 邮件的发送
///</summary>
public bool Send()
{
bool bResult = true;
try
{
if (mMailMessage != null)
{
mSmtpClient = new SmtpClient();
//mSmtpClient.Host = "smtp." + mMailMessage.From.Host;
mSmtpClient.Host = this.mSenderServerHost;
mSmtpClient.Port = this.mSenderPort;
mSmtpClient.UseDefaultCredentials = false;
mSmtpClient.EnableSsl = this.mEnableSsl;
if (this.mEnablePwdAuthentication)
{
System.Net.NetworkCredential nc = new System.Net.NetworkCredential(this.mSenderUsername, this.mSenderPassword);
//mSmtpClient.Credentials = new System.Net.NetworkCredential(this.mSenderUsername, this.mSenderPassword);
//NTLM: Secure Password Authentication in Microsoft Outlook Express
mSmtpClient.Credentials = nc.GetCredential(mSmtpClient.Host, mSmtpClient.Port, "NTLM");
}
else
{
mSmtpClient.Credentials = new System.Net.NetworkCredential(this.mSenderUsername, this.mSenderPassword);
}
mSmtpClient.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
mSmtpClient.Send(mMailMessage);
}
}
catch (Exception ex)
{
bResult = false;
Console.WriteLine(ex.ToString());
}
return bResult;
}
}大工告成！！！！！！！！！！！！！！！！！！！！11
如需Demo，请下载资源