Support user flags

[ojab]

1. Make IMAP account

2. Create a letter:

   C: RUBY0004 UID FETCH 2 flags
   S: * 1 FETCH (UID 2 FLAGS (\Seen \Draft $NotJunk NotJunk))
   

3. Add flag from Apple's Mail.app

   C: RUBY0004 UID FETCH 2 flags
   S: * 1 FETCH (UID 2 FLAGS (\Flagged \Seen \Draft $NotJunk NotJunk $MailFlagBit0))
   

4. Sync mailbox to another one using offlineimap v6.5.7 with this config (log with -d ALL)

5. Check a letter in the new mailbox:

   C: RUBY0004 UID FETCH 1 flags
   S: * 1 FETCH (UID 1 FLAGS (\Flagged \Seen \Draft))
   

IMAP server is dovecot-2.2.10 here.

[daniele-athome]

This could also be useful to associate with Gmail labels (I currently use IMAP keywords as labels, which is the closest thing).

[yeupou]

Hello.

Any known workaround?

[nodens]

I do have the same need (I tag emails using imap flags in sieve, and would like to sync them with offlineimap).

I saw https://github.com/OfflineIMAP/offlineimap/wiki/Syncing-custom-tags but didn't test it yet (especially IDK if it works with current, python3 version).