The operating system places incoming mail for you in a file that we
call your inbox. When you start up Rmail, it runs a C program
movemail to copy the new messages from your inbox into
your primary Rmail file, which also contains other messages saved from
previous Rmail sessions. It is in this file that you actually read the
mail with Rmail. This operation is called getting new mail. You
can get new mail at any time in Rmail by typing g.
rmail-primary-inbox-list contains a list of the
files which are inboxes for your primary Rmail file. If you don't set
this variable explicitly, it is initialized from the
means to use the default inbox. The default inbox is
or `/usr/mail/username', depending on your operating system.
Some sites use a method called POP for accessing users' inbox data
instead of storing the data in inbox files.
movemail can work
with POP if you compile it with the macro
and then install it setuid to
root. It is safe to install
movemail in this way.
Assuming you have compiled and installed
appropriately, you can specify a POP inbox with a "file name" of the
movemail handles such a name by
opening a connection to the POP server. The
variable specifies the machine to look for the server on.
There are three reason for having separate Rmail files and inboxes.
When getting new mail, Rmail first copies the new mail from the inbox file to the Rmail file; then it saves the Rmail file; then it truncates the inbox file. This way, a system crash may cause duplication of mail between the inbox and the Rmail file, but cannot lose mail.
movemail copies mail from an inbox in the system's mailer
directory, it actually puts it in an intermediate file
`~/.newmail-inboxname'. Once it finishes, Rmail reads that
file, merges the new mail, saves the Rmail file, and only then deletes
the intermediate file. If there is a crash at the wrong time, this file
continues to exist and Rmail will use it again the next time it gets new
mail from that inbox.