(C# UWP/WinRT) Rename Email Attachments After Adding

Demonstrates how to rename email attachments after adding but before sending.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// 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 = "MY_SMTP_USERNAME";
mailman.SmtpPassword = "MY_SMTP_PASSWORD";
mailman.SmtpSsl = true;
mailman.SmtpPort = 465;

Chilkat.Email email = new Chilkat.Email();

email.Subject = "This is a test";
email.Body = "This is a test";
email.From = "Chilkat Support <support@chilkatsoft.com>";
bool success = email.AddTo("Chilkat Admin","admin@chilkatsoft.com");
// To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

// Add some attachments.
// The AddFileAttachment method returns the value of the content-type it chose for the attachment.
string contentType = email.AddFileAttachment("qa_data/jpg/starfish.jpg");
if (email.LastMethodSuccess != true) {
    Debug.WriteLine(email.LastErrorText);
    return;
}

contentType = email.AddFileAttachment("qa_data/pdf/fishing.pdf");
if (email.LastMethodSuccess != true) {
    Debug.WriteLine(email.LastErrorText);
    return;
}

// If we save the email to a .eml, we can examine in a text editor.
success = email.SaveEml("qa_output/e1.eml");
if (success == false) {
    Debug.WriteLine(email.LastErrorText);
    Debug.WriteLine("Failed to save .eml");
    return;
}

// We see the following in the e1.eml
// Notice that Chilkat replaced the full path with just the filename.
// The full local path is not part of the email that gets sent..

// ...
// --------------020807050607070004010609
// Content-Type: image/jpeg; name="starfish.jpg"
// Content-Transfer-Encoding: base64
// Content-Disposition: attachment; filename="starfish.jpg"
// 
// ...
// --------------020807050607070004010609
// Content-Type: application/pdf; name="fishing.pdf"
// Content-Transfer-Encoding: base64
// Content-Disposition: attachment; filename="fishing.pdf"
// ...

// Before sending, each filename can be changed within the email object.
// For example:
success = email.SetAttachmentFilename(0,"orange_starfish.jpg");
success = email.SetAttachmentFilename(1,"tuna_fishing.pdf");

// Look at the new MIME source of the email in a  text editor...
success = email.SaveEml("qa_output/e2.eml");
if (success == false) {
    Debug.WriteLine(email.LastErrorText);
    Debug.WriteLine("Failed to save .eml");
    return;
}

// You'll see this:

// ...
// --------------020807050607070004010609
// Content-Type: image/jpeg; name="orange_starfish.jpg"
// Content-Transfer-Encoding: base64
// Content-Disposition: attachment; filename="orange_starfish.jpg"
// 
// ...
// --------------020807050607070004010609
// Content-Type: application/pdf; name="tuna_fishing.pdf"
// Content-Transfer-Encoding: base64
// Content-Disposition: attachment; filename="tuna_fishing.pdf"
// ...

// Send the email with the updated filenames..
success = await mailman.SendEmailAsync(email);
if (success != true) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

success = await mailman.CloseSmtpConnectionAsync();
if (success != true) {
    Debug.WriteLine("Connection to SMTP server not closed cleanly.");
}

Debug.WriteLine("Mail with attachments sent!");