从<>空发件人地址发送电子邮件

Question

Send-MailMessage
 -From "from@example.com"
 -To "to@example.com"
 -Subject "Subject" `
 -SmtpServer "localhost" -Body "Test Message"

I'm sending email using Send-MailMessage , the powershell equivalent of using System.Net.Mail.MailMessage.

Is there any way of sending email from the null sender address? If not are there any powershell/.NET alternatives I can use.

From is required so cannot be omitted. null, "" etc aren't acceptable because Send-MailMessage validates the from is an email address.

---

<> Null sender address : "The sender address is the email address that will receive email about delivery problems (mailing lists change this but not the From: email header so that they, and not the people sending to them, get messages about delivery problems). A special null sender address (MAIL FROM:<>) is used to signal that no one cares and no bounce notifications should be sent. Null senders are used when sending bounce messages themselves, and sometimes at other times."

Answer 1

You cannot do this with SmtpClient and MailMessage, so using this or Send-MailMessage is out of the question. Unfortunately that means you're left with either finding a third party library which does support it, or writing the code yourself to send directly through SMTP.

You're probably better off testing this part of your system with a unit test.

Answer 2

Manually with telnet

open localhost 25

HELO Foo
MAIL FROM: <>   <--- the null address

Automated.

Not actually the complete working code, but should give the general impression GetFile and SmtpStream are streams. The solution is to feed an pre-created .eml file by directly interacting with the SMTP protocol.

        GivenAClientIsConnectedToAnAgentInTheWAITINGState();

        SmtpStream.WriteAsciiString("MAIL FROM:<>{0}", Environment.NewLine);
        SmtpStream.ReceiveAsAsciiString();

        SmtpStream.WriteAsciiString("RCPT TO:<{0}>{1}",mailboxAddress, Environment.NewLine);
        SmtpStream.ReceiveAsAsciiString();

        SmtpStream.WriteAsciiString("DATA{0}", Environment.NewLine);
        SmtpStream.ReceiveAsAsciiString();
        SmtpStream.SendEmail(_fileRepository.GetFile("NullSenderMessage.eml"));
        SmtpStream.SendDataTerminator();
        SmtpStream.ReceiveAsAsciiString();
        SmtpStream.WriteAsciiString("QUIT");