! cmd   execute a shell command
-       move backward one message (no delete)
a nick  display an alias for a user
c[file] copy/append current message to file (default: prn)
d       delete current message
dq      delete current message and then quit
f user  forward current message to user
g num   make message num current message
H num   print subject of current message
h       print all subjects
m [-s subject] user     mail a message to user
n       move forward one message (no delete)
o option ...    Set one of the mail options:
O       Print the options set by the o command
p       print current message (P to use built-in pager)
q       quit with mailbox updated
r       reply to a message
s[file] save current message to file(s) (default =mbox)
t       print current message with headers (T to use built-in pager)
u       undelete current message
w[file] save current message to file(s) without header (default =mbox)
x       exit with mailbox restored
<num>   make message <num> the current message
