Provided by: nmh_1.3-1_i386
msgchk - check for messages
msgchk [-date | -nodate] [-notify all/mail/nomail ] [-nonotify
all/mail/nomail ] [-host hostname] [-user username] [-apop |
-noapop] [-kpop] [-sasl] [-saslmech mechanism] [-snoop] [users
The msgchk program checks all known mail drops for mail waiting for
you. For those drops which have mail for you, msgchk will indicate if
it believes that you have seen the mail in question before.
The -notify type switch indicates under what circumstances msgchk
should produce a message. The default is -notify all which says that
msgchk should always report the status of the users maildrop. Other
values for ‘type’ include ‘mail’ which says that msgchk should report
the status of waiting mail; and, ‘nomail’ which says that msgchk should
report the status of empty maildrops. The -nonotify type switch has
the inverted sense, so -nonotify all directs msgchk to never report the
status of maildrops. This is useful if the user wishes to check
msgchk’s exit status. A non-zero exit status indicates that mail was
not waiting for at least one of the indicated users.
If msgchk produces output, then the -date switch directs msgchk to
print out the last date mail was read, if this can be determined.
msgchk will normally check all the local mail drops, but if the option
“pophost:” is set in the mts configuration file “mts.conf”, or if the
-host hostname switch is given, msgchk will query this POP service host
as to the status of mail waiting.
The default is for msgchk to assume that your account name on the POP
server is the same as your current username. To specify a different
username, use the ‘-user username’ switch.
When using POP, you will normally need to type the password for your
account on the POP server, in order to retrieve your messages. It is
possible to automate this process by creating a “.netrc” file
containing your login account information for this POP server. For
each POP server, this file should have a line of the following form.
Replace the words mypopserver, mylogin, and mypassword with your own
machine mypopserver login mylogin password mypassword
This “.netrc” file should be owned and readable only by you.
For debugging purposes, there is also a switch -snoop, which will allow
you to watch the POP transaction take place between you and the POP
If nmh has been compiled with APOP support, the -apop switch will cause
msgchk to use APOP rather than standard POP3 authentication. Under
APOP, a unique string (generally of the format
<pid.timestamp@hostname>) is announced by the POP server. Rather than
‘USER user’, ‘PASS password’, msgchk sends ‘APOP user digest’, where
digest is the MD5 hash of the unique string followed by a ‘secret’
shared by client and server, essentially equivalent to the user’s
password (though an APOP-enabled POP3 server could have separate APOP
and plain POP3 passwords for a single user). -noapop disables APOP in
cases where it’d otherwise be used.
If nmh has been compiled with KPOP support, the -kpop switch will allow
msgchk to use Kerberized POP rather than standard POP3 on a given
invocation. If POPSERVICE was also #defined to "kpop", msgchk will be
hardwired to always use KPOP.
If nmh has been compiled with SASL support, the -sasl switch will
enable the use of SASL authentication. Depending on the SASL mechanism
used, this may require an additional password prompt from the user (but
the “.netrc” file can be used to store this password). The -saslmech
switch can be used to select a particular SASL mechanism.
If SASL authentication is successful, inc will attempt to negotiate a
security layer for session encryption. Encrypted traffic is labelled
with ‘(encrypted)’ and ‘(decrypted)’ when viewing the POP transaction
with the -snoop switch.
$HOME/.mh_profile The user profile
/etc/nmh/mts.conf nmh mts configuration file
/var/mail/$USER Location of mail drop
‘user’ defaults to the current user