仅供参考，以帮助扩展Action Script 3.0信息库。我无法找到任何方法来做我上面所要求的。下面是我用来发送带有附件的电子邮件的方法。https://code.google.com/p/airxmail/
http://flex.coltware.com/as3-flex-air/airxmail/

import com.coltware.airxmail.INetAddress;
import com.coltware.airxmail.MailSender.SMTPSender;
import com.coltware.airxmail.MimeMessage;
import com.coltware.airxmail.RecipientType;

private function send_plain_email():void{
//  How to send plain text email
var sender:SMTPSender = new SMTPSender();
sender.setParameter(SMTPSender.HOST,"your.smtp.hostname");
sender.setParameter(SMTPSender.PORT,25);  // default port is 25
// If you use SMTP-AUTH
sender.setParameter(SMTPSender.AUTH,true);
sender.setParameter(SMTPSender.USERNAME,"username");
sender.setParameter(SMTPSender.PASSWORD,"password");

// Create email message
var message:MimeMessage = new MimeMessage();

//  Set from email address and reciepients
var from:INetAddress = new INetAddress("from-email-address@xxxx.yyyy","from label");
message.setFrom(from);

var toRecpt:INetAddress = new INetAddress("to-email-address@xxxx.yyyy","to label");
message.addRcpt(RecipientType.TO,toRecpt);

var ccRecpt:INetAddress = new INetAddress("cc-email-address@xxxx.yyyy","cc label");
message.addRcpt(RecipientType.CC,ccRecpt);

//  
message.setSubject("hello world");
//
//  Plain Text Part
//
var textPart:MimeTextPart = new MimeTextPart();
message.setSubject("Reciept for #" + job.jobs.JobID);
textPart.contentType.setParameter("charset","UTF-8");
textPart.transferEncoding = "8bit";
textPart.setText("Please see attached PDF \n You will need a PDF viewer to open \n To download the latest version of Adobe Acrobat reader, Please follow the link: http://www.adobe.com/products/acrobat/readstep.html");
message.addChildPart(textPart);

//
//  Attachment part 
//
    var filePart:MimeImagePart = new MimeImagePart();
    filePart.contentType.setMainType("application");
    filePart.contentType.setSubType("pdf");
           filePart.setAttachementFile(File.desktopDirectory.resolvePath(sfile),"WorkOrder.pdf");
            message.addChildPart(filePart);

            sender.send(message);
            sender.close();
}