8.2 What to mark for

mu4e supports a number of marks:

mark for/as  | keybinding  | description
'something'  | *, <insert> | mark now, decide later
delete       | D, <delete> | delete
flag         | +           | mark as 'flagged' ('starred')
move         | m           | move to some maildir
read         | !           | mark as read
refile       | r           | mark for refiling
trash        | d           | move to the trash folder
untrash      | =           | remove 'trash' flag
unflag       | -           | remove 'flagged' mark
unmark       | u           | remove mark at point
unmark all   | U           | remove all marks
unread       | ?           | marks as unread
action       | a           | apply some action

After marking a message, the left-most columns in the headers view indicate the kind of mark. This is informative, but if you mark many (say, thousands) messages, this slows things down significantly14. For this reason, you can disable this by setting mu4e-headers-show-target to nil.

something is a special kind of mark; you can use it to mark messages for ‘something’, and then decide later what the ‘something’ should be15 Later, you can set the actual mark using M-x mu4e-mark-resolve-deferred-marks (#). Alternatively, mu4e will ask you when you try to execute the marks (x).



this uses an Emacs feature called overlays, which are slow when used a lot in a buffer


This kind of ‘deferred marking’ is similar to the facility in dired, midnight commander (https://www.midnight-commander.org/) and the like, and uses the same key binding (insert).