(C#) Send Email with Multiple Reply-To Addresses

Send email with multiple repy-to addresses.

Note: Some mail servers will remove the extra email addresses from the Reply-To header. Even if you provide multiple reply-to addresses, the email may arrive with only the 1st.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.MailMan mailman = new Chilkat.MailMan();

mailman.SmtpHost = "smtp.my_mail_server.com";
mailman.SmtpUsername = "myUsername";
mailman.SmtpPassword = "myPassword";
mailman.SmtpPort = 465;
mailman.SmtpSsl = true;

// Create a new email object
Chilkat.Email email = new Chilkat.Email();

email.Subject = "This is a test";
email.Body = "This is a test";
email.From = "Joe <joe@example.com>";
bool success = email.AddTo("Mary","mary@example2.com");

// Specify a single reply-to address, which will get replace with a list of addresses..
email.ReplyTo = "placeholder@example.com";

// Get the email as MIME.
Chilkat.StringBuilder sbMime = new Chilkat.StringBuilder();
mailman.RenderToMimeSb(email,sbMime);

// Update the Reply-To MIME header with a list of email addresses.
string replyToAddrs = "joe@example.com, mike@example.com";
sbMime.ReplaceAllBetween("Reply-To: ","\r\n",replyToAddrs,false);

// Examine the MIME to be sent:
Debug.WriteLine(sbMime.GetAsString());

// Here's the MIME:

// MIME-Version: 1.0
// Date: Tue, 03 Sep 2024 08:18:12 -0500
// Message-ID: <D892B0E563A7A13B1F499530DE21529714EA479A@SLICE>
// Content-Type: text/plain; charset=us-ascii; format=flowed
// Content-Transfer-Encoding: 7bit
// X-Priority: 3 (Normal)
// Subject: This is a test
// From: Joe <joe@example.com>
// To: Mary <mary@example2.com>
// Reply-To: joe@example.com, mike@example.com
// 
// This is a test

// ---------
// Send the MIME...
success = mailman.SendMime("joe@example.com","mary@example2.com",sbMime.GetAsString());
if (success == false) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

success = mailman.CloseSmtpConnection();
if (success == false) {
    Debug.WriteLine("Connection to SMTP server not closed cleanly.");
}

Debug.WriteLine("Mail Sent!");