• mutt-patched;
• offlineimap (>= 6.5.7);
• abook;
• catdoc;
• make.

Examine configs carefully and replace John Doe with your account requisites.

Do the first synchronization with make sync (it can take a lot of time when your Gmail account keeps a lot of mail) and see which folders were created under the Mail directory. Then specify all folders you want to see in the Mutt's sidebar in the mailboxes configuration option in the muttrc configuration file. The minimal folder set is "MyInbox" (see below), "Drafts", "Sent Mail", "Spam" and "Trash". Here you also can add any of your favorite labels.

make ui will start the Mutt.

make sync will start a single synchronization process. The command is something that you can put into your crontab.

make clean will remove all caches and logs BUT local maildirs will not be affected. If you want to remove them too do it by hand with rm -rf Mail.

Here are the main navigation key bindings:

• Arrow Down - next folder;
• Arrow Up - previous folder;
• Arrow Right - select folder;
• j - next message;
• k - previous message.

The main goal is to provide message threads view like Gmail web UI does.

"INBOX" IMAP folder is not good enough for the main mail folder used in Mutt because sent mail is not appear in the folder (but Gmail web UI shows it there). Because of this threads in Mutt index consists only of received mail. You can "fix" it by explicit save sent messages with "set record = +INBOX" but all messages sent by web UI or mobile client will be not affected. The second inconvinience is when you open web UI after sending message with Mutt you will see your sent message twice in the thread.

There is a special IMAP folder called "[Gmail]/All Mail". All messages sent with Mutt, web UI or other clients will appear in the folder automagically, BUT you can not remove any messages from the folder! When you do so, offlineimap tool will remove the messages on the remote side and everything looks great until next synchronization which will bring all "removed" messages back to the local folder. So the "All Mail" folder does not fits our needs too.

I have fixed the thing creating an extra label in the Gmail web UI (say, MyInbox). How it works:

1. All incoming mail moved to MyInbox with Gmail filter;
2. All outgoing mail labelled with "MyInbox" with another Gmail filter;
3. Mutt points to "MyInbox" IMAP folder as the main folder;

The only inconvinience is the Inbox will always be empty when you visit your account with web UI or mobile client. You should look to the MyInbox label instead to find your mails.

All other aims are achieved:

• threads consists of all mails (received and sent) in all clients and without any duplication. Message sent from one client will be successfully displayed by any other clients;
• mails and threads can be easily removed in all clients.

1. Login into the account;
2. Got to the settings page;
3. Set language to English (because actual label names are translated to the language);
4. Create "MyInbox" label;
5. Go to "Inbox" and add a filter which labels all incoming messages with "MyInbox". Set filter condition to "size is more than 1 byte";
6. Go to "Sent Mail" and add a filter which labels all sent messages with "MyInbox". Set filter condition to "size is more than 1 byte";
7. Mark all messages in "Inbox" and "Sent Mail" with "MyInbox" label.

Actual IMAP folder names can differ from account to account. I saw differences like "[Gmail]/Drafts" and "[Google Mail]/Drafts".

I have tested with offlineimap git-cloned from official https://github.com/OfflineIMAP/offlineimap because it is too old in Debian. Installation is straightforward:

git clone https://github.com/OfflineIMAP/offlineimap /home/john.doe/bin/offlineimap

and set OFFLINEIMAP variable in the Makefile to /home/john.doe/bin/offlineimap/offlineimap.py.