发送到类似System.Net.Mail.SmtpClient的文件夹

Question

我正在使用MailKit.Net.Smtp.SmtpClient，我正在试图弄清楚是否有一种方法可以配置此客户端，使其将电子邮件拖放到文件夹中，就像PickupDirectoryLocation属性影响System.Net.Mail.SmtpClient dotNet实例一样。这里需要的是开发和调试，这样我们就可以安全地捕获会发出的消息。

我对另一种调试MailKit生成的电子邮件的技术持开放态度，只要它不涉及任何外部服务(如SMTP服务器(。

Answer 1

这样做的方法是执行以下操作：

public static void SaveToPickupDirectory (MimeMessage message, string pickupDirectory)
{
do {
// Generate a random file name to save the message to.
var path = Path.Combine (pickupDirectory, Guid.NewGuid ().ToString () + ".eml");
Stream stream;
try {
// Attempt to create the new file.
stream = File.Open (path, FileMode.CreateNew);
} catch (IOException) {
// If the file already exists, try again with a new Guid.
if (File.Exists (path))
continue;
// Otherwise, fail immediately since it probably means that there is
// no graceful way to recover from this error.
throw;
}
try {
using (stream) {
// IIS pickup directories expect the message to be "byte-stuffed"
// which means that lines beginning with "." need to be escaped
// by adding an extra "." to the beginning of the line.
//
// Use an SmtpDataFilter "byte-stuff" the message as it is written
// to the file stream. This is the same process that an SmtpClient
// would use when sending the message in a `DATA` command.
using (var filtered = new FilteredStream (stream)) {
filtered.Add (new SmtpDataFilter ());
// Make sure to write the message in DOS (<CR><LF>) format.
var options = FormatOptions.Default.Clone ();
options.NewLineFormat = NewLineFormat.Dos;
message.WriteTo (options, filtered);
filtered.Flush ();
return;
}
}
} catch {
// An exception here probably means that the disk is full.
//
// Delete the file that was created above so that incomplete files are not
// left behind for IIS to send accidentally.
File.Delete (path);
throw;
}
} while (true);
}