I can't speak for everyone, but here's what I am using. I do have 'messages' directory which contains 'imap' and 'archive'. messages \-imap \-archive The imap directory is being synchronized via offlineimap to the server. In the offlineimap postsync hook I call a script which does some bookkeeping on the newly received messages and it also marks old and already read and not flagged emails by the 'old-tread' tag. N=notmuch while : ; do AGE=100d # 100 days # Find all threads containing old messages OLD_MESSAGES=$( $N search --output=threads not tag:archive and date:..$AGE and not tag:unread and not tag:flagged ) [ -n "$OLD_MESSAGES" ] || break # Find threads containing newer messages NEW_MESSAGES=$( $N search --output=threads not tag:archive and not '(' date:..$AGE or tag:unread or tag:flagged ')' ) # remove the threads containing newer messages OLD_THREADS=$( /usr/xpg4/bin/fgrep -v -x -f <(echo "$NEW_MESSAGES") < <(echo "$OLD_MESSAGES") ) [ -n "$OLD_THREADS" ] || break $N tag +old-thread -- $OLD_THREADS break done # If old thread received newer message, unmark it too $N tag -old-thread -- tag:old-thread and '(' not date:..$AGE or tag:unread or tag:flagged or tag:archive ')' Once in a while I review the old-thread messages and assign them by hand 'archive' flag. The postsync hook is looking for this flag and moves all messages to be archived into archive folder. You can list files to be archived by $N search --output=files 'path:imap/**' tag:archive I won't list the commands to move files from messages/imap to messages/archive since I have a bit more complex scenario. But it should be straightforward. On next run offlineimap sees that the messages disappeared from 'imap' folder and removes them from imap server. $ notmuch count '*' 734346 $ notmuch count 'path:imap/**' 18419 In my case I am server side filtering the emails into several folders so that I have at least some order in emails when reading email via phone, so 'path:imap/**' contains all the messages in whole imap tree. $ notmuch count 'path:imap/** and tag:inbox and tag:unread' 11 I'm trying to have my virtual INBOX empty most of the time. I'm interested what tricks others use! Cheers -- Vlad