Question

代码背后：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Net.Mail;
using System.Net;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
    MailMessage msg = new MailMessage();
    msg.From = new MailAddress(txtfrom.Text, "OLMS");
    msg.To.Add(new MailAddress(txtto.Text));
    msg.Subject = txtsub.Text;
    msg.Body = txtbody.Text;
    msg.IsBodyHtml = true;

    SmtpClient smtp = new SmtpClient();
    smtp.Host = "smtp.gmail.com";
    smtp.Credentials = new NetworkCredential(txtfrom.Text, txtto.Text);

    smtp.EnableSsl = true;

    smtp.Send(msg);

    lblresult.Text = "Message Sent Successful!";

}
}

堆栈追踪：

[SocketException (0x2746): An existing connection was forcibly closed by the remote host]
System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, 
SocketFlags socketFlags) +6416371
System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size) +130

[IOException: Unable to read data from the transport connection: 
An existing connection was         forcibly closed by the remote host.]
System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, 
Int32 size) +296
System.Net.DelegatedStream.Read(Byte[] buffer, Int32 offset, Int32 
count) +45
System.Net.BufferedReadStream.Read(Byte[] buffer, Int32 offset, 
Int32 count) +106
System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader 
caller, Boolean oneLine) +203
System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader 
caller) +16
System.Net.Mail.CheckCommand.Send(SmtpConnection conn, String& 
response) +54
System.Net.Mail.StartTlsCommand.Send(SmtpConnection conn) +28
System.Net.Mail.SmtpConnection.GetConnection(ServicePoint 
servicePoint) +843
System.Net.Mail.SmtpTransport.GetConnection(ServicePoint 
servicePoint) +170
System.Net.Mail.SmtpClient.GetConnection() +44
System.Net.Mail.SmtpClient.Send(MailMessage message) +1554
[SmtpException: Failure sending mail.]
System.Net.Mail.SmtpClient.Send(MailMessage message) +1906
_Default.Button1_Click(Object sender, EventArgs e) in c:\Users
\Azhar Khan\Documents\Visual Studio 2010\WebSites
\WebSite2\Default.aspx.cs:31
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +9553594
System.Web.UI.WebControls.Button.RaisePostBackEvent(String 
eventArgument) +103
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.R
aisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler 
sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +35
System.Web.UI.Page.ProcessRequestMain(Boolean 
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1724

我没有为SMTP配置IIS（我不知道是否要这样做）。我还没有在这个wesite中将任何smtp配置添加到Web.config文件中。关于我收到的异常的任何帮助都阻止我发送电子邮件。感谢

Answer 1

确保在https://google.com/settings/security/lesssecureapps的Google帐户设置中启用允许安全性较低的应用选项 - 从2014年下半年开始，需要使用基本身份验证通过Gmail SMTP进行身份验证

或者，您可以禁用上述选项并实施XOAUTH2进行SMTP身份验证（请参阅https://developers.google.com/gmail/xoauth2_protocol）。

Answer 2

您的代码似乎是smtp.EnableSsl = true;启用SSL。如果您想以相同的方式执行此操作，请使用465端口。以下是相关问题的已解决答案链接：

How can I send emails through SSL SMTP with the .NET Framework?

如果您发现任何困难，请告诉我。

发送邮件。 Asp.net。 C＃。远程主机强制关闭现有连接

2 个答案: