C.1 General

1. Does mu4e provide context-sensitive help information? Yes — pressing H should take you to the right section in this manual.
2. How can I quickly delete/move/trash a lot of messages? You can select (’mark’ in emacs-speak) the messages like you would select text in a buffer; the actions you then take (e.g., DEL for delete, m for move and t for trash) apply to all selected messages. You can also use functions like mu4e-headers-mark-thread (T), mu4e-headers-mark-subthread (t) to mark whole threads at the same time, and mu4e-headers-mark-pattern (%) to mark all messages matching a certain regular expression.
3. mu4e seems to return a subset of all matches — how can I get them all? For speed reasons, mu4e returns only up to the value of the variable mu4e-search-result-limit (default: 500) matches. To show all, use M-x mu4e-headers-toggle-full-search (Q), or customize the variable mu4e-headers-full-search. This applies to all search commands.
4. Can I automatically apply the marks on messages when leaving the headers buffer? Yes you can — see the documentation for the variable mu4e-headers-leave-behavior.
5. How can I set mu4e as the default e-mail client in emacs? See Emacs default.
6. Can mu4e use some fancy Unicode characters instead of these boring plain-ASCII ones? Glad you asked! Yes, if you set mu4e-use-fancy-chars to t, mu4e uses such fancy characters in a number of places. Since not all fonts include all characters, you may want to install the unifont and/or symbola fonts on your system.
7. Can I start mu4e in the background? Yes — if you provide a prefix-argument (C-u), mu4e starts, but does not show the main-window.
8. Does mu4e support searching for CJK (Chinese-Japanese-Korean) characters? Yes, if you have Xapian 1.2.8 or newer, and set the environment variable XAPIAN_CJK_NGRAM to non-empty before indexing, both when using mu from the command-line and from mu4e.
9. How can I customize the function to select a folder? The mu4e-completing-read-function variable can be customized to select a folder in any way. The variable can be set to a function that receives five arguments, following completing-read. The default value is ido-completing-read; to use emacs’s default behavior, set the variable to completing-read. Helm users can use the same value, and by enabling helm-mode use helm-style completion.
10. I have a lot of Maildir folders, so regenerating them each time makes things slow. What can I do? Set mu4e-cache-maildir-list to t (but make sure to read its docstring).
11. How can I hide certain message from the search results? See the variable mu4e-headers-hide-predicate.
12. I’m getting an error ’Variable binding depth exceeds max-specpdl-size’ when using mu4e – what can I do about it? The error occurs because mu4e is binding more variables than emacs allows for, by default. You can avoid this by setting a higher value, e.g. by adding the following to your configuration:

    (setq max-specpdl-size 5000)