Missing header of multipart after a writeTo(). Help!

Question

Hello!
What I want is to get the pure MIME message from a writeTo() method. And I don't want to use MimeMessage since it needs a Session -that I don't have-.
Basicaly, I create a MimeMultipart with different MimeBodyParts. Then I ask writeTo() on the MimeMultipart. I do get the parts separeted by boundaries, but I got NO headers such as the following ones:
Content-Type: multipart/mixed;
boundary=" ... "
The question is: How do I get these missing headers?
Here is a piece of my code
//create a default (multipart/mixed) MIME mutlipart
MimeMultipart okMultiPart = new MimeMultipart();
okMultiPart.addBodyPart( (MimeBodyPart)mbp1 );
okMultiPart.addBodyPart( (MimeBodyPart)mbp2 );
ByteArrayOutputStream pout = new ByteArrayOutputStream();
messageContent.writeTo(pout);
What am I missing?

Answer 1

Hello Amichai,
well I know about the getDefaultInstance, but it might contain sensitive informations that I don't want to appear in the MIME message. Typically it gets a Message-ID with a user name. I do not want that.
(BTW is there any way to erase is ? setHeader("Message-ID","") or removeHeader("Message-ID") do not work...)
This is why I wanted another way to get the MIME message.
Is there for instance a clean way to get the boundary from the multipart? if yes I could set it as a header by myself ....