Exporting to eml/mbox files

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This section describes "non-Thunderbird" exports using a standard folder structure.


Courex exports eml and/or mbox files to individual folders which preserves your Courier folder structure. Courex creates the folder tree from the base "Export Destination Folder" which you specify, starting with a 'Courex' folder.


If you don't specify an "Export Destination Folder" it will default to your Courier 'box' file folder if this was found at startup. If no 'box' file was found automatically, the destination folder will default to 'C:\' (thus, the export will be to 'C:\Courex').


For example, if you specify a base folder for export of "D:\Email" and you store your emails in Courier according to year, such as "Sent Mail\2005", "Sent Mail\2006", etc., Courex will export all mails from "Sent Mail\2005" into folder "D:\Email\Courex\Sent Mail\2005". If you selected "Create mbox" files. D:\Email\Courex\Sent Mail\2005 will contain a file named "2005.mbox".


The name of the eml files, if produced, is derived from the UTC adjusted date and time of the email. Thus, alphabetical order is also date/time order. Courex uses this to enter eml files into mbox files in date/time order. Courex also uses the eml file names to detect potential duplicates. If two messages have exactly the same date and time, and thus the same eml file name, an entry will be made in the Export.log file and the suffix 'A' (and 'B'. 'C', etc. if necessary) will be appended to the eml file name.


The mbox file produced via eml files will differ from that produced directly. The directly produced mbox will contain messages in the order they were encountered in the Courier database, while that produced from eml files will contain messages in date/time order. That is, the mbox files will contain the same messages, and will be the same size, but the order of the messages will be different. Potential duplicates can only be detected if eml files are produced, so the Export.log file may differ too.


An 'eml' file contains one email in the same form in which it was received or sent. That is, it will usually consist of only 7-bit ASCII characters (extended characters in various international character sets are represented by combinations of 7-bit characters) and will have a maximum line length of 76 characters. It is complete with header, body text and attachments, binary attachments being usually encoded in "base64" format (a way of representing 8-bit bytes using only 7-bit printable ASCII characters). You can open an eml file in a text editor and read it (though it might be difficult to understand if it contains a lot of extended character encodings and/or if it is in html form and, of course, binary attachments will simply look like strings of random characters).


A 'mbox' file contains multiple 'eml' files, divided by a separator line. Thunderbird uses the mbox format as its native database format, which is why it was relatively easy to extend Courex to include the special Thunderbird support.


The 'eml' and 'mbox' files should contain the email exactly as it was originally sent or received. But because of the way that Courier stores messages in its database, requiring them to be reconstructed, this is almost never the case for emails exported by Courex. However, the exported emails conform to RFC822 and MIME standards (that is, they are in transmissible form) and have the same appearance and contents as the original email (unless they have been edited by the user within Courier).