How can I send two messages through javamail so that Outlook can put them in the same conversation?

Question

At some point, I sent an email, and it is processed and accepted by the exchange server, and then viewed by the Outlook client. At a later point, I am sending another email where it is the answer / associated with the 1st email. I want Outlook to know that they are connected to each other and group them together when I group letters on the phone.

A few caveats:

• I will not have access to the first object of the email message for reply.
• When composing the second letter, I will have the subject, messageID and body of the first letter.

I tried to add the header fields "in-reply-to" and "reference" in the second letter, but Outlook will not discuss them. However, Thunderbird and Gmail will use them.

Answer 1

When grouping messages into a conversation, Outlook most likely will not use the header fields, but rather a subject line. He will ignore words like Fw: and Re :.

Try adding a Re: message to the first message and use it as the second message.

Link: http://lifehacker.com/157042/make-outlook-thread-conversations-like-gmail