By default, mu4e uses the xdg-open-program 23 or (on OS X) the open program for opening attachments. If you want to use another program, you do so by setting the MU_PLAY_PROGRAM environment variable to the program to be used.
The default directory for extracting (saving) attachments is your home directory
(~/); you can change this using the variable
(setq mu4e-attachment-dir "~/Downloads")
For more flexibility,
mu4e-attachment-dir can also be a user-provided function.
This function receives two parameters: the file-name and the mime-type as found in the e-mail
message24 of the attachment, either or
both of which can be nil. For example:
(setq mu4e-attachment-dir (lambda (fname mtype) (cond ;; docfiles go to ~/Desktop ((and fname (string-match "\\.doc$" fname)) "~/Desktop") ;; ... other cases ... (t "~/Downloads")))) ;; everything else
You can extract multiple attachments at once by prefixing the extracting command by C-u; so C-u e asks you for a range of attachments to extract (for example, 1 3-6 8). The range "‘a’" is a shortcut for all attachments.