This is a proof-of-concept someone wrote, but I have no idea how tested it is: http://git.zx2c4.com/gmail-notmuch/ http://git.zx2c4.com/gmail-notmuch/ It syncs

This is a proof-of-concept someone wrote, but I have no idea how tested it is: http://git.zx2c4.com/gmail-notmuch/ http://git.zx2c4.com/gmail-notmuch/ It syncs Gmail labels to notmuch tags. As I understand it: by default, Gmail treats labels as IMAP folders, which means a standard IMAP exporter will end up with multiple copies of messages with more than one label. The workaround is to only export the "All Mail" folder, and then add support for Gmail's custom attributes, namely retrieving the X-GM-LABELS [1] attribute for each message and then doing something with it (in this case, storing it as notmuch tags). [1] https://developers.google.com/gmail/imap_extensions#access_to_gmail_labels_x-gm-labels https://developers.google.com/gmail/imap_extensions#access_t...