A script that converts mbox files to maildir folders.
This version has been updated to use python 3. The source is from the patched v0.2 version made by Jon Schewe (specifically, this commit from 2008). Jon's version appears that it was based on the script this mailing list post presented but which is no longer at the specified link.
I used this with Python 3.7 to convert mbox files generated by exporting folders from Mac Mail on Mojave into maildir folders.