默认的Windows电子邮件客户端不允许从我的WPF应用发送消息

Question

我正在尝试从WPF应用程序向默认Windows 10邮件客户端发送一封带有附件的电子邮件。 MailUtility类准备要发送的邮件

public static class MailUtility
    {
        //Extension method for MailMessage to save to a file on disk
        private static void Save(this MailMessage message, string filename, bool addUnsentHeader = true)
        {
            using (var filestream = File.Open(filename, FileMode.Create))
            {
                if (addUnsentHeader)
                {
                    var binaryWriter = new BinaryWriter(filestream);
                    //Write the Unsent header to the file so the mail client knows this mail must be presented in "New message" mode
                    binaryWriter.Write(System.Text.Encoding.UTF8.GetBytes("X-Unsent: 1" + Environment.NewLine));
                }

                var assembly = typeof(SmtpClient).Assembly;
                var mailWriterType = assembly.GetType("System.Net.Mail.MailWriter");

                // Get reflection info for MailWriter contructor
                var mailWriterContructor = mailWriterType.GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, null, new[] { typeof(Stream) }, null);

                // Construct MailWriter object with our FileStream
                var mailWriter = mailWriterContructor.Invoke(new object[] { filestream });

                // Get reflection info for Send() method on MailMessage
                var sendMethod = typeof(MailMessage).GetMethod("Send", BindingFlags.Instance | BindingFlags.NonPublic);

                sendMethod.Invoke(message, BindingFlags.Instance | BindingFlags.NonPublic, null, new object[] { mailWriter, true, true }, null);

                // Finally get reflection info for Close() method on our MailWriter
                var closeMethod = mailWriter.GetType().GetMethod("Close", BindingFlags.Instance | BindingFlags.NonPublic);

                // Call close method
                closeMethod.Invoke(mailWriter, BindingFlags.Instance | BindingFlags.NonPublic, null, new object[] { }, null);
            }
        }

        public static string PrepareEmlFile(string subject, string fromAddress, IEnumerable<string> toAddresses, IList<IAttachment> attachments, string body)
        {
            if (string.IsNullOrWhiteSpace(fromAddress))
            {
                fromAddress = "GebenSieIhre@Adressee.in";
            }
            var mailMessage = new MailMessage
            {
                From = new MailAddress(fromAddress),
                Subject = subject,
                IsBodyHtml = true,
                Body = body
            };

            if (toAddresses != null)
            {
                foreach (var address in toAddresses.Where(s => string.IsNullOrWhiteSpace(s) == false))
                {
                    mailMessage.To.Add(address);
                }
            }

            if (attachments != null)
            {
                foreach (var attachment in attachments)
                {
                    Attachment attachmentRaw = null;

                    if (attachment.FileData != null)
                    {
                        var ms = new MemoryStream(attachment.FileData);
                        attachmentRaw = new Attachment(ms, attachment.FileName, attachment.MimeType);
                    }
                    else if (File.Exists(attachment.FileName))
                    {
                        attachmentRaw = new Attachment(attachment.FileName, attachment.MimeType);
                    }

                    mailMessage.Attachments.Add(attachmentRaw);
                }
            }

            var tempFile = Path.GetTempFileName();
            var filename = Path.ChangeExtension(tempFile, "eml");

            mailMessage.Save(filename);
            mailMessage.Dispose();

            return filename;
        }
    }

发送邮件的方法

 public void SendViaSystemDefautClient(string subject, string fromAddress, IEnumerable<string> toAddress, IList<IAttachment> attachments, string body = "")
        {
            try
            {
                var prepareEmlFile = MailUtility.PrepareEmlFile(subject, fromAddress, toAddress, attachments, body);

                Process.Start(prepareEmlFile);
            }
            catch (Exception e)
            {
                Logger.Error(e,"Failed to send e-mail using system default mail client.");
                MessageHub.PushExceptionMessage(LangToXaml.ErrorSendingLetter);
            }
        }

执行代码后，将启动默认的Windows电子邮件，其中包含有关发送者和接收者以及附件的信息。我无法编辑此数据，也无法发送此消息

Result