Gmail 发送电子邮件作为回复

Question

通过 gmail 发送电子邮件非常简单，如下所示：

Sending email in .NET through Gmail

但我似乎找不到发送电子邮件作为对另一封电子邮件的回复的方法。自动包括以前的消息。

乐趣代码：与发送电子邮件无关（阅读此处，使用 AE.Net.Mail imap 客户端库）

 public GmailConnector()
    {
        StringBuilder sb1 = new StringBuilder();
        using (var context = new SupportDataContext())
        using (var client = new ImapClient("imap.gmail.com", "xxxx@gmail.com", "xxx", AuthMethods.Login, 993, true))
        {
            client.SelectMailbox("INBOX");
            Console.WriteLine(client.GetMessageCount());
            var mm = client.SearchMessages(SearchCondition.Seen(), false, true);
            foreach (var m in mm)
            {
                if (m.Value == null)
                    continue;

                var msg = m.Value;
                var emailRef = msg.To.First().Address;
                SupportThread supportThread = null;
                if (emailRef.Contains("+"))
                {
                    var supportThreadRef = emailRef.Substring(emailRef.IndexOf('+') + 1, emailRef.IndexOf('@') - emailRef.IndexOf('+') - 1);
                    var supportThreadId = long.Parse(supportThreadRef);
                    supportThread = context.SupportThreads.First(x => x.Id == supportThreadId);
                }
                else if (msg.Subject.Contains("RE:"))
                {
                    var subjectRef = msg.Subject.Replace("RE:", "").Trim();
                    var tmpDate = msg.Date.AddDays(-7);
                    var tmpSupportThread = context.SupportThreads.FirstOrDefault(x => x.EntryDate < msg.Date && x.EntryDate > tmpDate && x.Title.Equals(subjectRef));
                    if (tmpSupportThread != null)
                        supportThread = tmpSupportThread;
                }
                if (supportThread == null)
                {
                    supportThread = new SupportThread();
                    supportThread.Title = msg.Subject;
                    supportThread.Creator = msg.From.Address;
                    supportThread.CreatorName = msg.From.DisplayName;
                    supportThread.EntryDate = msg.Date;
                }
                var responseMessage = msg.AlternateViews.GetHtmlView().Body;
                responseMessage.Substring(0, responseMessage.IndexOf(REPLY_SEPERATOR)); 
                var tmpEmailMessage = new EmailMessage();
                tmpEmailMessage.EntryDate = msg.Date;
                tmpEmailMessage.InnerContent = responseMessage;
                tmpEmailMessage.SenderEmail = msg.From.Address;
                tmpEmailMessage.SenderDisplayName = msg.From.DisplayName;
                tmpEmailMessage.Title = msg.Subject;
                tmpEmailMessage.SupportThread = supportThread;
                foreach (var attachment in m.Value.Attachments)
                {
                    var tmpAttachment = new Attachment();
                    tmpAttachment.Data = attachment.GetData();
                    tmpAttachment.Name = attachment.Filename;
                    tmpAttachment.EmailMessage = tmpEmailMessage;
                    context.Attachments.InsertOnSubmit(tmpAttachment);
                }
                context.EmailMessages.InsertOnSubmit(tmpEmailMessage);
                context.SubmitChanges(); 
            }
        }

        var fromAddress = new MailAddress("from@gmail.com", "From Name");
        var toAddress = new MailAddress("to@example.com", "To Name");
        const string fromPassword = "fromPassword";
        const string subject = "Subject";
        const string body = "Body";

        var smtp = new SmtpClient
        {
            Host = "smtp.gmail.com",
            Port = 587,
            EnableSsl = true,
            DeliveryMethod = SmtpDeliveryMethod.Network,
            UseDefaultCredentials = false,
            Credentials = new NetworkCredential(fromAddress.Address, fromPassword)
        };
        using (var message = new System.Net.Mail.MailMessage(fromAddress, toAddress)
        {
            Subject = subject,
            Body = body,

        })
        {
            smtp.Send(message);
        }
        Console.Read();
    }

Answer 1

只需接收收到的电子邮件，读出发件人、主题、文本等数据，并在创建回复时使用它们。回复的目的地应该是发件人的邮箱地址，subject = "RE:"+subject+incoming，至于正文你可以用任何你想要的方法。我不认为有任何用于回复电子邮件的内置功能。你必须手动做这些事情。首先你得想办法把邮件客户端邮箱里的内容弄出来，比如outlook或者手动从SMTP服务器下载最近的X封邮件。

检索原始电子邮件（通过 OLE 从 Outlook-> COM 对象 -> outlook ole 对象就像您安装的 outlook 邮件客户端的用户代理）。Google 如何做到这一点。或从 SMTP 下载最新邮件。
获得邮件内容后，创建一封包含传入邮件内容的电子邮件。然后发送。如果您使用 Microsoft OLE，那么您也可以通过 outlook ole 对象发送电子邮件。

Answer 2

回复消息非常简单。大多数情况下，您只需像创建任何其他消息一样创建回复消息。只有一些细微的差别：

在回复邮件中，如果您要回复的邮件中不存在前缀，则您需要在 Subject header 前加上 "Re: " 前缀（在换句话说，如果您回复的消息的 Subject 为 "Re: party tomorrow night!"，您会 而不是 加上另一个 "Re: ").
您需要将回复邮件的 In-Reply-To header 设置为原始邮件中 Message-Id header 的值。
您需要将原始消息的 References header 复制到回复消息的 References header 中，然后附加原始消息的 Message-Id header.
您可能希望在回复中 "quote" 原始消息的文本。

如果用代码来表达这个逻辑，它可能看起来像这样（我在这个例子中使用 MailKit）：

public static MimeMessage Reply (MimeMessage message, bool replyToAll)
{
    var reply = new MimeMessage ();

    // reply to the sender of the message
    if (message.ReplyTo.Count > 0) {
        reply.To.AddRange (message.ReplyTo);
    } else if (message.From.Count > 0) {
        reply.To.AddRange (message.From);
    } else if (message.Sender != null) {
        reply.To.Add (message.Sender);
    }

    if (replyToAll) {
        // include all of the other original recipients - TODO: remove ourselves from these lists
        reply.To.AddRange (message.To);
        reply.Cc.AddRange (message.Cc);
    }

    // set the reply subject
    if (!message.Subject.StartsWith ("Re:", StringComparison.OrdinalIgnoreCase))
        reply.Subject = "Re: " + message.Subject;
    else
        reply.Subject = message.Subject;

    // construct the In-Reply-To and References headers
    if (!string.IsNullOrEmpty (message.MessageId)) {
        reply.InReplyTo = message.MessageId;
        foreach (var id in message.References)
            reply.References.Add (id);
        reply.References.Add (message.MessageId);
    }

    // quote the original message text
    using (var quoted = new StringWriter ()) {
        var sender = message.Sender ?? message.From.Mailboxes.FirstOrDefault ();

        quoted.WriteLine ("On {0}, {1} wrote:", message.Date.ToString ("f"), !string.IsNullOrEmpty (sender.Name) ? sender.Name : sender.Address);
        using (var reader = new StringReader (message.TextBody)) {
            string line;

            while ((line = reader.ReadLine ()) != null) {
                quoted.Write ("> ");
                quoted.WriteLine (line);
            }
        }

        reply.Body = new TextPart ("plain") {
            Text = quoted.ToString ()
        };
    }

    return reply;
}

注意：此代码假定 message.TextBody 不为空。有可能，尽管不太可能发生这种情况（这意味着消息不包含 text/plain body）。

Gmail 发送电子邮件作为回复

Gmail Send Email As Reply

c#

smtp