我尝试在25、587等不同的端口上尝试将服务器更改为localhost，并将UseDefaultCredentials设置为false，ssl设置为false。
仍然无效。它给我一个错误：“电子邮件发送失败”。
private void button4_Click(object sender, EventArgs e)
{
try
{
MailMessage myMsg = new MailMessage();
myMsg.From = new MailAddress("@yahoo.com");
myMsg.To.Add("@yahoo.com");
myMsg.Subject = "Subject " + textBox1.Text;
myMsg.Body = "Body " + textBox2.Text;
// your remote SMTP server IP.
SmtpClient smtp = new SmtpClient("smtp.mail.yahoo.com");
smtp.Port = 465;
smtp.UseDefaultCredentials = false;
smtp.Credentials = new System.Net.NetworkCredential("@yahoo.com", "psw");
smtp.EnableSsl = true;
smtp.Send(myMsg);
}
catch (SmtpException ex)
{
MessageBox.Show("E-mail unsuccesful "+ ex);
}
}
我已经制作了一个类来测试SMTP发送
class SmtpTests
{
//Normal port 25 text,465 SSL,587 text thn STARTSSL
protected static log4net.ILog Log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
static int connectionTimeout = 1300;
/// <summary>
/// Tests the SMTP server and try to send a test Email
/// </summary>
/// <param name="login"></param>
/// <param name="password"></param>
/// <param name="server">Server DNS name</param>
/// <param name="port"></param>
/// <param name="forceSsl"></param>
/// <param name="from"></param>
/// <param name="to"></param>
/// <param name="msg">Message to send to the body</param>
/// <param name="log">Detailed Log</param>
/// <param name="resume">Resumed Log</param>
/// <param name="error">Erro Log</param>
/// <param name="checkcertificate">Check if SSL Certificate in the Server is acceptable</param>
/// <param name="trystartssl">try to send the command STARTTLS</param>
/// <returns></returns>
public static bool ScanSMTP(string login, string password, string server, int port, bool forceSsl,
string from, string to, string msg,
out string log, out string resume, out string error,
bool checkcertificate = true, bool trystartssl = true)
{
#region check parameters
log = Environment.NewLine;
error = "";
resume = "";
string _fromaddrstr = "";
string _toaddrstr = "";
string _errorResume = $"[FAIL] Port={port}, Force SSL={forceSsl}, try STARTSSL={trystartssl}";
System.Net.Mail.MailAddress addr = null;
if (!String.IsNullOrEmpty(login))
{
if (String.IsNullOrEmpty(password))
{
error = "If login is not empty than the password cannot be empty";
log += "!! Error : " + error;
resume = Environment.NewLine + $"[FAIL] 'password' is missing" + Environment.NewLine;
return false;
}
}
try
{
addr = new System.Net.Mail.MailAddress(from);
_fromaddrstr = addr.Address;
}
catch
{
error = "'from' email address is incorrect.";
log += "!! Error : " + error;
resume = Environment.NewLine + $"[FAIL] 'from' incorrect format > '{from}'" + Environment.NewLine;
return false;
}
try
{
addr = new System.Net.Mail.MailAddress(to);
_toaddrstr = addr.Address;
}
catch
{
error = "'to' email address is incorrect.";
log += "!! Error : " + error;
resume = Environment.NewLine + $"[FAIL] 'to' incorrect format > '{to}'" + Environment.NewLine;
return false;
}
#endregion
try
{
#region support variables
string _response = "";
string _msgfotter = "";
StreamReader clearTextReader = null;
StreamWriter clearTextWriter = null;
StreamReader sslreader = null;
StreamWriter sslwriter = null;
SslStream sslStream = null;
// Depending on checkcertificate value stream may ignore Certificate Errors
// like: Hostname not in the certificate and Certificate Chain Errors
SslStream GetSslStream(Stream innerstream)
{
if (checkcertificate)
return new SslStream(innerstream);
else
return new SslStream(
innerstream,
false,
new RemoteCertificateValidationCallback((s, c, h, e) => true),
null
);
}
#endregion
#region support internal methods
void ExitError(string str, ref string _log, ref string _error)
{
_error = str;
_log += "!! Error : " + str + Environment.NewLine + Environment.NewLine;
if (sslStream == null)
{
clearTextWriter.WriteLine("QUIT");
}
else
{
sslwriter.WriteLine("QUIT");
}
}
string AskReceive(string commandline, ref string _log)
{
if (sslStream == null)
{
_log += "> " + commandline + Environment.NewLine;
clearTextWriter.WriteLine(commandline);
string _str;
System.Threading.Thread.Sleep(200);
//while (!clearTextReader.EndOfStream)
//while (!String.IsNullOrEmpty(_str))
// {
// System.Threading.Thread.Sleep(200);
// //yield return _str;
// _str = clearTextReader.ReadLine();
// _log += "< " + _str + Environment.NewLine;
//}
_str = clearTextReader.ReadLine();
_log += "< " + _str + Environment.NewLine;
return _str;
}
else
{
_log += "> " + commandline + Environment.NewLine;
sslwriter.WriteLine(commandline);
System.Threading.Thread.Sleep(200);
string _str = sslreader.ReadLine();
_log += "< " + _str + Environment.NewLine;
return _str;
}
}
bool Login(ref string _log, ref string _error)
{
if (!(_response = AskReceive($"AUTH LOGIN", ref _log)).StartsWith("334"))
{
ExitError(_response, ref _log, ref _error);
return false;
}
if (!(_response = AskReceive(Convert.ToBase64String(Encoding.UTF8.GetBytes($"{login}")), ref _log)).StartsWith("334"))
{
ExitError(_response, ref _log, ref _error);
return false;
}
if (!(_response = AskReceive(Convert.ToBase64String(Encoding.UTF8.GetBytes($"{password}")), ref _log)).StartsWith("235"))
{
ExitError(_response, ref _log, ref _error);
return false;
}
return true;
}
bool SendMsg(ref string _log, ref string _error)
{
// HELO JakesDominoApp
// MAIL FROM: [email protected]
// RCPT To: jhowlett@EITS
// DATA
// From: My Self <[email protected]>
// To: A secret list <[email protected]>
// Subject: A simple test
// Mime-Version: 1.0;
// Content-Type: text/html; charset="ISO-8859-1";
// Content-Transfer-Encoding: 7bit;
//
// <html>
// <body>
// <h2>An important link to look at!</h2>
// Here's an <a href="http://www.codestore.net">important link</a>
// </body>
// </html>
// .
// QUIT
if (!String.IsNullOrEmpty(login))
if (!Login(ref _log, ref _error))
return false;
if (!(_response = AskReceive($"MAIL FROM: <{_fromaddrstr}>", ref _log)).StartsWith("250"))
{
ExitError(_response, ref _log, ref _error);
return false;
}
if (!(_response = AskReceive($"RCPT TO: <{_toaddrstr}>", ref _log)).StartsWith("250"))
{
ExitError(_response, ref _log, ref _error);
return false;
}
string _return = AskReceive($"DATA", ref _log);
if (_return.Substring(0, 1) == "5")
{
ExitError(_return, ref _log, ref _log);
return false;
}
string _details = $"Server:'{server}' | Login:'{login}' | port:{port} | try STARTTSL:{trystartssl} | Force SSL:{forceSsl}";
if (!AskReceive(
$"From: {from}" + Environment.NewLine +
$"To: {to}" + Environment.NewLine +
$"Subject: " + _details +
Environment.NewLine + Environment.NewLine +
msg + Environment.NewLine + Environment.NewLine +
"__________________________________________________" + Environment.NewLine + Environment.NewLine +
_details + " " + _msgfotter + Environment.NewLine +
Environment.NewLine + Environment.NewLine + ".", ref _log).StartsWith("250"))
{
ExitError(_response, ref _log, ref _error);
return false;
}
AskReceive($"QUIT", ref _log);
return true;
}
#endregion
#region method body
TcpClient client = new TcpClient();
//Make the connection with timeout
if (!client.ConnectAsync(server, port).Wait(connectionTimeout))
{
//log = ex.ExceptionToString();
error = $"Could not connect '{server}' at port '{port}'";
log += Environment.NewLine + error + Environment.NewLine;
resume = Environment.NewLine + $"[FAIL] Port={port}. Could not connect '{server}' at port '{port}'" + Environment.NewLine;
return false;
}
using (client)
{
if (forceSsl)
{
using (NetworkStream stream = client.GetStream())
using (sslStream = GetSslStream(stream)) // new SslStream(stream))
{
sslStream.AuthenticateAsClient(server);
using (sslreader = new StreamReader(sslStream))
using (sslwriter = new StreamWriter(sslStream) { AutoFlush = true })
{
log += Environment.NewLine + Environment.NewLine + "## SSL connection (safe)" + Environment.NewLine;
string connectResponse = sslreader.ReadLine();
log += "< " + connectResponse + Environment.NewLine;
if (!connectResponse.StartsWith("220"))
{
ExitError(_response, ref log, ref error);
resume = Environment.NewLine + $"[FAIL] Port={port}, Force SSL={forceSsl} (encrypted)";
return false;
}
if (!(_response = AskReceive($"HELO {Dns.GetHostName()}", ref log)).StartsWith("250"))
{
ExitError(_response, ref log, ref error);
resume = Environment.NewLine + $"[FAIL] Port={port}, Force SSL={forceSsl} (encrypted)";
return false;
}
_msgfotter = $"Encrypted MSG using SMTP/S on port: {port}";
if (SendMsg(ref log, ref error))
{ resume = Environment.NewLine + $"[SUCCESS] Port={port}, Force SSL={forceSsl} (encrypted)"; return true; }
else
{ resume = Environment.NewLine + $"[FAIL] Port={port}, Force SSL={forceSsl} (encrypted)"; return false; }
}
}
}
else //Not SMTP/S (SSL)
{
using (NetworkStream stream = client.GetStream())
using (clearTextReader = new StreamReader(stream))
using (clearTextWriter = new StreamWriter(stream) { AutoFlush = true })
{
log += Environment.NewLine + Environment.NewLine + "## Plain text connection (UNSAFE)" + Environment.NewLine;
string connectResponse = clearTextReader.ReadLine();
log += "< " + connectResponse + Environment.NewLine;
if (!connectResponse.StartsWith("220"))
{
ExitError(connectResponse, ref log, ref error);
resume = Environment.NewLine + $"[FAIL] Port={port}, Force SSL={forceSsl} (unsafe, plain text)";
return false;
}
if (!(_response = AskReceive($"HELO {Dns.GetHostName()}", ref log)).StartsWith("250"))
{
ExitError(_response, ref log, ref error);
resume = Environment.NewLine + $"[FAIL] Port={port}, Force SSL={forceSsl} (unsafe, plain text)";
return false;
}
if (trystartssl)
{
if ((_response = AskReceive("STARTTLS", ref log)).StartsWith("220"))
{
clearTextReader = null;
clearTextWriter = null;
using (sslStream = GetSslStream(stream)) // new SslStream(stream))
{
//TLS Start
sslStream.AuthenticateAsClient(server);
log += Environment.NewLine + Environment.NewLine + "## TLS connection (safe)" + Environment.NewLine;
using (sslreader = new StreamReader(sslStream))
using (sslwriter = new StreamWriter(sslStream) { AutoFlush = true })
{
if (!AskReceive($"HELO {Dns.GetHostName()}", ref log).StartsWith("250"))
{ ExitError(_response, ref log, ref error); resume = $"[FAIL] Port={port}, Force SSL={forceSsl} (encrypted)"; return false; }
_msgfotter = "Encrypted MSG using STARTSSL on port: " + port.ToString();
if (SendMsg(ref log, ref error))
{
resume = Environment.NewLine +
$"[SUCCESS] Port={port}, Force SSL={forceSsl}, try STARTSSL={trystartssl} (encrypted)";
return true;
}
else
{
resume = Environment.NewLine +
$"[FAIL] Port={port}, Force SSL={forceSsl}, try STARTSSL={trystartssl} (encrypted)";
return false;
}
}
}
}
}
if ((trystartssl && !_response.StartsWith("220")) || !trystartssl)
{
if (trystartssl)
log += "## Does not accept StartSSL" + Environment.NewLine;
_msgfotter = "Unsafe MSG using plain text on port: " + port.ToString();
if (SendMsg(ref log, ref error))
{
resume = Environment.NewLine +
$"[SUCCESS] Port={port}, Force SSL={forceSsl}, try STARTSSL={trystartssl} (unsafe, plain text)";
return true;
}
else
{
resume = Environment.NewLine +
$"[FAIL] Port={port}, Force SSL={forceSsl}, try STARTSSL={trystartssl} (unsafe, plain text)";
return false;
}
}
return false;
}
}
}
#endregion
}
catch (Exception ex)
{
if (ex.Message == @"The remote certificate is invalid according to the validation procedure.")
{
log += $"The host name '{server}' must exist in the server SSL certificate. Don't use IP or host names not in the Certificate" + Environment.NewLine;
}
error = ex.Message;
log += "!! Error : " + ex.Message + Environment.NewLine;
resume += Environment.NewLine + _errorResume;
return false;
}
}
}