There are times when you need to restore an email from evolution's cache. This script does that and turns cached message into an mbox file.
Check out this git repo
git clone https://github.com/lutter/assembox.git
cd assembox
Make sure you have ruby installed and simply run assembox like this
./bin/assembox -d ~/.cache/evolution/mail/7/INBOX -o /tmp/mails.mbox
The argument to -d is a evolution cache directory. You can use -m to
restore just one message from that directory.
This has worked for me; if it breaks for you, you get to keep both parts.
The way evolution organizes a cache directory (in version 3.6.4) is that plain messages get stored in a file 'N.' where N is a number; MIME messages are stored in a number of files: the first is 'N.HEADER' which contains the message headers, and then for each part files 'N(.M)*.MIME' for the MIME headers for a part and 'N(.M)*' for the body of a part. As the overall message can form a tree of parts, fun ensues restoring the tree and figuring out the right MIME boundary strings.
Restoring a message into an mbox amounts to little more than cating the files into the mbox file, together with a little extra padding like a 'From' line, the right MIME boundaries, and plenty of blank lines in the right places.
This script is licensed under the GPL v3; see the file LICENSE for details