binding synchronise mailbox function

[Eric Smith]

I want to bind the `$' command to the space key. Is it possible to
bind the mailbox synchronise function?

Could not find anything useful in the docs so went:

[eric@apple ~] 5 $ nm `which mutt`|grep  sync
0806ed40 t maildir_sync_message
0806b108 T mbox_sync_mailbox
0806ee94 T mh_sync_mailbox
0806eb8c t mh_sync_message
080709d8 T mx_sync_mailbox
08070220 t sync_mailbox

But all of these gave an error viz:
:bind index <space> sync_mailbox
sync_mailbox: no such function in map


-- 
Eric Smith