In Haiku, each email message is stored as a separate file with email-related attributes (ie., From, To, Subject, Status, etc.). In contrast, Thunderbird stores all messages for any given folder in a standard plain text mbox file, where all messages are concatenated in a single file (more details about mbox, in case you are curious). Fortunately, there is a rather simple way to migrate your Thunderbird messages to Haiku email files, by using a little known command line utility called mbox2mail. This small but useful command line program converts mbox email files into individual Haiku email files and adds their corresponding email file type attributes.
