mboxdiff.py

mboxdiff.py

import mailbox

# Open the mbox files (relative to your present working directory)
# Note, Mail.app actually exports a mbox folder that contains an mbox file
mbox1 = mailbox.mbox('Old-Archive.mbox/mbox')
mbox2 = mailbox.mbox('New-Archive.mbox/mbox')

# Use something like `subject` to unique the messages
# or they will all be unique.
def subjects(mbox):
	subjects = []
	for message in mbox:
		subjects.append(message['subject'])
	return subjects

old_subjects = subjects(mbox1)
new_subjects = subjects(mbox2)

# Throw away dups within a mailbox
# and remove all `new_subjects` from the `old_subjects` set
diff = list(set(old_subjects) - set(new_subjects))

# Just the unsynced subjects are left
for subject in diff:
	print subject