Getting envelope object using JavaMail

Question

I'm building a mail client for Android and using JavaMail to get the messages via Imap Protocol. I'm saving the Message-Id header for every message I reveive and I came across a message that didn't contain any Message-Id header in it's original message but when I receive the message from Gmail via Imap I get a field called Envalope and this field happens to contain all the data I need including the Message-Id.

The problem is that I can't reach that Envelope object no matter what I do and I was wondering if someone has already done that and can throw some tips.

The original message came with the following content:

MIME-Version: 1.0
From: "Mailbox Support" <support@mailboxapp.com>
To: ******
Subject: Tips for Using Mailbox in Gmail
Content-Type: multipart/alternative;
 boundary="----mailcomposer-?=_1-1369421942466"

------mailcomposer-?=_1-1369421942466

Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

[some text]

------mailcomposer-?=_1-1369421942466

Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

[Some rich text]

------mailcomposer-?=_1-1369421942466--

Thanks a lot

Answer 1

JavaMail uses the information in the IMAP ENVELOPE as the return values for methods such as getMessageID. Normally that will be the same data you would get using getHeader("Message-ID"), but if the Message-ID header is missing in the original message the server might "make up" a value to return in the ENVELOPE.

Answer 2

1. get hold of folder which you want to read like store.getFolder("INBOX") and assign it to a variable which is of type Folder

2. get all messages from above folder variable as folder.getMessages()

3. when you loop over on each message cast message to (IMAPMessage) and assign it to a variable of type IMAPMessage

4. as _getEnvelope is private method in IMAPMessage, you need to you reflection to get access to it as follow

   Method method = IMAPMessage.class.getDeclaredMethod("_getEnvelope", null); method.setAccessible(true); ENVELOPE envelope = (ENVELOPE) method.invoke(imapMessage, null);

5. from envelope object you can access to messageId and rest of the details