When you receive mail locally, 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 called 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 that are inboxes for your primary Rmail file. If you don't set
this variable explicitly, Rmail uses the MAIL environment
variable, or, as a last resort, a default inbox based on
rmail-spool-directory. The default inbox file depends on your
operating system; often it is /var/mail/username,
You can specify the inbox file(s) for any Rmail file for the current
session with the command
set-rmail-inbox-list; see Rmail Files.
There are two reasons for having separate Rmail files and inboxes.
Rmail uses the standard ‘mbox’ format, introduced by Unix and
GNU systems for inbox files, as its internal format of Rmail files.
(In fact, there are a few slightly different mbox formats. The
differences are not very important, but you can set the variable
rmail-mbox-format to tell Rmail which form your system uses.
See that variable's documentation for more details.)
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
clears out the inbox file. This way, a system crash may cause
duplication of mail between the inbox and the Rmail file, but cannot
lose mail. If
rmail-preserve-inbox is non-
Rmail does not clear out the inbox file when it gets new mail. You
may wish to set this, for example, on a portable computer you use to
check your mail via POP while traveling, so that your mail will remain
on the server and you can save it later on your main desktop
In some cases, Rmail copies the new mail from the inbox file indirectly. First it runs the movemail program to move the mail from the inbox to an intermediate file called .newmail-inboxname, in the same directory as the Rmail file. Then Rmail merges the new mail from that file, 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.
If Rmail is unable to convert the data in .newmail-inboxname into mbox format, it renames the file to RMAILOSE.n (n is an integer chosen to make the name unique) so that Rmail will not have trouble with the data again. You should look at the file, find whatever message confuses Rmail (probably one that includes the control-underscore character, octal code 037), and delete it. Then you can use 1 g to get new mail from the corrected file.