At some point, I’ve sent an email and it is processed and received by an exchange server and then viewed by an outlook client. At a later point, I send another email where it is a reply/related to the 1st email. I want outlook to know that they are related and group them together when I group emails by conversation.
A couple of caveats:
- I won’t have access to the 1st email’s message object to reply off of.
- I will have the subject, messageID, and body of the first email when composing the 2nd email.
I’ve tried adding the “in-reply-to” and “references” header fields in the 2nd email, but outlook will not conversate them. Thunderbird and Gmail will thread them appropriately, though.
When grouping messages into a Conversation, Outlook will most likely not use the header fields but rather the subject line. It will ignore words like Fw: and Re:.
Try prepend a Re: to the first message subject and use this as second message subject.
Ref: http://lifehacker.com/157042/make-outlook-thread-conversations-like-gmail