guys.
Can anyone explain how mailing messages are organized into threads? As I understood, messages are sent always to the same email of the group. So there has to be some identifier of thread…
guys. Can anyone explain how mailing messages are organized into threads? As I understood,
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Every Email message has a unique
Message-IDheader.Every reply has an
In-Reply-Toand/orReferencesheader.This is enough to do a topological sort and put the messages into threads.
[update]
For the gory details, see RFC 5322 (the specification for Internet mail messages). Search for "Message-ID", "References", and "In-Reply-To". Strictly speaking, these headers are optional because the spec uses "SHOULD" and not "MUST" when describing them. In practice, I have never seen an Email message that did not include a Message-ID except for spam, and I have never seen a mail client that did not include one or both reply headers in replies.