我正在使用gmail smtp发送邮件： 主持人：smtp.gmail.com 端口：587
在MVC应用程序中使用gmail smtp发送邮件时遇到异常。 下面的代码用于发送邮件：
public static int SendMail(string StrFromAdd, string StrEmailTo, string StrSubject, string StrContents,
string SMTPServer, int SMTPPort, string SMTPUserName, string SMTPPassword,
string attachment = "", string CC = "", string BCC = "")
{
try
{
AlternateView AV = null;
System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
System.Net.Mail.MailMessage message = new System.Net.Mail.MailMessage();
System.Net.Mail.MailAddress fromAddress = new System.Net.Mail.MailAddress(StrFromAdd, "Test");
smtpClient.Host = SMTPServer;
smtpClient.Port = SMTPPort;
smtpClient.Credentials = new System.Net.NetworkCredential(SMTPUserName, SMTPPassword);
smtpClient.EnableSsl = true;
message.From = fromAddress;
if (attachment != null)
{
string[] attachmentsarr = attachment.Split(';');
foreach (string attach in attachmentsarr)
{
if (attach != "")
message.Attachments.Add(new Attachment(attach));
}
}
string pattern = @"^((([\w]+\.[\w]+)+)|([\w]+))@(([\w]+\.)+)([A-Za-z]{1,3})$";
if (StrEmailTo != "")
{
if (StrEmailTo.IndexOf(',') > -1)
{
string[] _strArrstrEmailTo = StrEmailTo.Split(',');
foreach (object objBCCEmailID in _strArrstrEmailTo)
if (Regex.IsMatch(objBCCEmailID.ToString().Trim(), pattern))
message.To.Add(new System.Net.Mail.MailAddress(objBCCEmailID.ToString().Trim()));
}
else
message.To.Add(new System.Net.Mail.MailAddress(StrEmailTo.ToString().Trim()));
}
if (CC != "")
{
if (CC.IndexOf(',') > -1)
{
string[] _strArrstrEmailCC = CC.Split(',');
foreach (object objBCCEmailID in _strArrstrEmailCC)
if (Regex.IsMatch(objBCCEmailID.ToString().Trim(), pattern))
message.CC.Add(new System.Net.Mail.MailAddress(objBCCEmailID.ToString().Trim()));
}
else
message.CC.Add(new System.Net.Mail.MailAddress(CC.ToString().Trim()));
}
if (BCC != "")
{
if (BCC.IndexOf(',') > -1)
{
string[] _strArrstrEmailBCC = BCC.Split(',');
foreach (object objBCCEmailID in _strArrstrEmailBCC)
if (Regex.IsMatch(objBCCEmailID.ToString().Trim(), pattern))
message.Bcc.Add(new System.Net.Mail.MailAddress(objBCCEmailID.ToString().Trim()));
}
else
message.Bcc.Add(new System.Net.Mail.MailAddress(BCC.ToString().Trim()));
}
// This is added for custom form & email template image
List<string> ImageFiles = Common.GetImagesInHTMLString(StrContents);
if (ImageFiles != null && ImageFiles.Count > 0)
{
string addStrContents = string.Empty;
for (int i = 0; i < ImageFiles.Count; i++)
{
// this is for custom form
if (ImageFiles[i].Contains("CustomFormImage"))
{
string Path = Regex.Match(ImageFiles[i], "<img.+?src=[\"'](.+?)[\"'].+?>", RegexOptions.IgnoreCase).Groups[1].Value;
int pos = Path.LastIndexOf("\\") + 1;
string FullPath = HttpContext.Current.Server.MapPath("~/img/CustomFormImage/" + Path.Substring(pos, Path.Length - pos));
if (System.IO.File.Exists(FullPath))
{
//addStrContents = addStrContents + "<img style='width:100px;height:100px;' src=\"cid:" + Path.Substring(pos, Path.Length - pos).Split('.')[0] + "\">" + Environment.NewLine;
StrContents = StrContents.Replace(Path, "cid:" + Path.Substring(pos, Path.Length - pos).Split('.')[0]);
}
}
// this is for email template image
else if (ImageFiles[i].Contains("EmailHeaderFooterImgs"))
{
string Path = Regex.Match(ImageFiles[i], "<img.+?src =[\"'](.+?)[\"'].+?>", RegexOptions.IgnoreCase).Groups[1].Value;
int pos = Path.LastIndexOf("\\") + 1;
if (System.IO.File.Exists(Path))
{
//addStrContents = addStrContents + "<img style='width:100px;height:100px;' src=\"cid:" + Path.Substring(pos, Path.Length - pos).Split('.')[0] + "\">" + Environment.NewLine;
StrContents = StrContents.Replace(Path, "cid:" + Path.Substring(pos, Path.Length - pos).Split('.')[0]);
}
}
}
AV = AlternateView.CreateAlternateViewFromString(StrContents, null, MediaTypeNames.Text.Html);
for (int i = 0; i < ImageFiles.Count; i++)
{
// this is for custom form
if (ImageFiles[i].Contains("CustomFormImage"))
{
string Path = Regex.Match(ImageFiles[i], "<img.+?src=[\"'](.+?)[\"'].+?>", RegexOptions.IgnoreCase).Groups[1].Value;
int pos = Path.LastIndexOf("\\") + 1;
string FullPath = HttpContext.Current.Server.MapPath("~/img/CustomFormImage/" + Path.Substring(pos, Path.Length - pos));
if (System.IO.File.Exists(FullPath))
{
//FileStream fs = new FileStream(FullPath, FileMode.Open, FileAccess.Read);
//Attachment a = new Attachment(fs, Path.Substring(pos, Path.Length - pos), MediaTypeNames.Application.Octet);
//message.Attachments.Add(a);
//addStrContents = addStrContents + "<img src=\"cid:" + Path.Substring(pos, Path.Length - pos).Split('.')[0] + "\">" + Environment.NewLine;
LinkedResource Img = new LinkedResource(FullPath, MediaTypeNames.Image.Jpeg);
Img.ContentId = Path.Substring(pos, Path.Length - pos).Split('.')[0];
AV.LinkedResources.Add(Img);
}
}
// this is for email template image
else if (ImageFiles[i].Contains("EmailHeaderFooterImgs"))
{
string Path = Regex.Match(ImageFiles[i], "<img.+?src =[\"'](.+?)[\"'].+?>", RegexOptions.IgnoreCase).Groups[1].Value;
int pos = Path.LastIndexOf("\\") + 1;
if (HttpContext.Current != null)
{
string FullPath = HttpContext.Current.Server.MapPath("~/EmailHeaderFooterImgs/" + Path.Substring(pos, Path.Length - pos));
if (System.IO.File.Exists(Path))
{
LinkedResource Img = new LinkedResource(Path, MediaTypeNames.Image.Jpeg);
Img.ContentId = Path.Substring(pos, Path.Length - pos).Split('.')[0];
AV.LinkedResources.Add(Img);
}
}
}
}
}
message.Subject = StrSubject;
message.IsBodyHtml = true;
if (AV != null)
message.AlternateViews.Add(AV);
else
message.Body = StrContents;
smtpClient.Send(message);
message.Dispose();
return 1;
}
catch (Exception ex)
{
}
}
下面是堆栈跟踪：
System.Security.Authentication.AuthenticationException: A call to SSPI failed, see inner exception. System.ComponentModel.Win32Exception: The function requested is not supported
at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.Mail.SmtpConnection.Flush()
at System.Net.Mail.ReadLinesCommand.Send(SmtpConnection conn)
at System.Net.Mail.EHelloCommand.Send(SmtpConnection conn, String domain)
at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)
at System.Net.Mail.SmtpClient.GetConnection()
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at MVC.Common.SendMails.SendMail(String StrFromAdd, String StrEmailTo, String StrSubject, String StrContents, String SMTPServer, Int32 SMTPPort, String SMTPUserName, String SMTPPassword, String attachment, String CC, String BCC) in SendMails.cs:line 296
注意：相同的代码在另一个应用程序中运行，该应用程序托管在同一服务器上，并且使用相同的gmail配置发送邮件。
答案 0 :(得分：0)
假设您的代码是针对（例如）.NET Framework 4.7.2编译的，那么请确保您的Web.config包括：
<httpRuntime targetFramework="4.7.2" />
如果您的targetFramework设置太低或丢失，则编译后的代码将自动尝试请求TLS 1.2（从.NET Framework 4.7起），但是目标运行时不支持它，因此错误。
（记入this SO answer，这使我意识到这里出了什么问题-尽管该问题和该问题并非重复。）