AppleScript - extract an email message as a MIME object - macos

Question

I have an AppleScript I wrote to do some parsing on Mail.app messages, however it seems I will need more powerful processing (specifically - separate a replied message from the original message it quotes) than what is provided by AppleScript (say, using Python's email package). Is it possible to get an email message as a MIME string?

Answer 1

I'm not sure if this is what you meant, but here is how you can get the raw message text from a selection you've made in Mail.app which can than be processed with MIME tools to extract all the parts.
tell application "Mail"
set msgs to selection
if length of msgs is not 0 then
repeat with msg in msgs
set messageSource to source of msg
set textFile to "/Users/harley/Desktop/foo.txt"
set myFile to open for access textFile with write permission
write messageSource to myFile
close access myFile
end repeat
end if
end tell
And then here's a Python email example script that unpacks the message and writes out each MIME part to a separate file in a directory
https://docs.python.org/3.4/library/email-examples.html
#!/usr/bin/env python3
"""Unpack a MIME message into a directory of files."""
import os
import sys
import email
import errno
import mimetypes
from argparse import ArgumentParser
def main():
parser = ArgumentParser(description="""\
Unpack a MIME message into a directory of files.
""")
parser.add_argument('-d', '--directory', required=True,
help="""Unpack the MIME message into the named
directory, which will be created if it doesn't already
exist.""")
parser.add_argument('msgfile')
args = parser.parse_args()
with open(args.msgfile) as fp:
msg = email.message_from_file(fp)
try:
os.mkdir(args.directory)
except FileExistsError:
pass
counter = 1
for part in msg.walk():
# multipart/* are just containers
if part.get_content_maintype() == 'multipart':
continue
# Applications should really sanitize the given filename so that an
# email message can't be used to overwrite important files
filename = part.get_filename()
if not filename:
ext = mimetypes.guess_extension(part.get_content_type())
if not ext:
# Use a generic bag-of-bits extension
ext = '.bin'
filename = 'part-%03d%s' % (counter, ext)
counter += 1
with open(os.path.join(args.directory, filename), 'wb') as fp:
fp.write(part.get_payload(decode=True))
if __name__ == '__main__':
main()
So then if the unpack.py script is run on the AppleScript output...
python unpack.py -d OUTPUT ./foo.txt
You get a directory with the MIME parts separated. When I run this on a message which quotes an original message then the original message shows up in a separate part.