Question

我正在编写一个根据输入的电子邮件地址和密码发送电子邮件的应用程序。从应用程序发送电子邮件我有点新鲜。我想知道如何处理那里的不同端口号。例如，gmail需要587，而雅虎需要465，而rediff需要25。对所有这些都没有一个解决方案吗？这听起来很愚蠢但是SMTP服务器地址或端口会随着时间而改变吗？

Answer 1

如果供应商方（google，yahoo等）的管理员打算更改其政策，则Ports可能会发生变化。所以AFAIK没有任何统一的解决方案，而是拥有此设置的XML文档并在您的应用中使用它。

Answer 2

System.Net.Mail.SmtpClient允许您使用构造函数传入端口。

SmtpClient client = new SmtpClient("mail.google.com:587");
client.Send("bob@bob.com", "jim@jim.com", "Subject", "Test Message");

只需根据您使用的构造函数修改“host”字符串即可。通常，邮件服务将使用非标准SMTP端口来防止滥用/渗透攻击等。

Answer 3

一直在使用这样的解决方案来解决问题。

public static bool SendEmail(MailMessage message)
{
    try
    {
        // call the full overload of if GetSMTPClient you want to override the default settings
        using (SmtpClient smtp = GetSMTPClient(true))
        {
            smtp.Send(message);
        }
        return true;
    }
    catch (Exception exception)
    {
        Elmah.ErrorSignal.FromCurrentContext().Raise(exception);
        return false;
    }
}

/// <summary>
/// Gets the default SMTP Client (Gmail here)
/// </summary>
/// <param name="isSetAtWebConfig">Has all the settings been specified at web.config</param>
/// <returns>Gets the default SMTP Client</returns>
public static SmtpClient GetSMTPClient(bool isSetAtWebConfig)
{
    try
    {
        SmtpClient client;
        if (isSetAtWebConfig)
        {
            client = new SmtpClient();
        }
        else
        {
            client = GetSMTPClient("smtp.gmail.com", 587, true,
                SmtpDeliveryMethod.Network, false,
                "someone@gmail.com", "somepass");
        }
        return client;
    }
    catch (Exception exception)
    {
        Elmah.ErrorSignal.FromCurrentContext().Raise(exception);
        throw;
    }
}

/// <summary>
/// Gets the SMTP Client with custom settings default settings
/// </summary>
/// <param name="host">SMTP Host</param>
/// <param name="port">SMTP Port</param>
/// <param name="enableSSL">Has SMTP enabled SSL</param>
/// <param name="delieveryMethod">SMTP Delivery Method</param>
/// <param name="useDefaultCredentials">Is SMTP using Default Credentials</param>
/// <param name="fromAddress">SMTP Client UserName</param>
/// <param name="fromPassword">SMTP Client Password</param>
/// <returns>Gets the new custom created SMTP Client</returns>
public static SmtpClient GetSMTPClient(string host, int port, 
    bool enableSSL, SmtpDeliveryMethod delieveryMethod, 
    bool useDefaultCredentials, 
    string fromAddress, string fromPassword)
{
    try
    {
        return new SmtpClient
        {
            Host = host,
            Port = port,
            EnableSsl = enableSSL,
            DeliveryMethod = delieveryMethod,
            UseDefaultCredentials = useDefaultCredentials,
            Credentials = new NetworkCredential(fromAddress, fromPassword)
        };
    }
    catch (Exception exception)
    {
        Elmah.ErrorSignal.FromCurrentContext().Raise(exception);
        throw;
    }
}

希望这有帮助。

不同端口的外发电子邮件问题

3 个答案: