specified interval. For more advanced options, see the Fetchmail man page,
which is well written and documents all options in detail.
CAUTION
Because the .fetchmailrc file contains your mail server password, it
should be readable only by you. This means that it should be owned by you
and should have permissions no greater than 600 . Fetchmail complains and
refuses to start if the .fetchmailrc file has permissions greater than
this.Choosing a Mail Delivery Agent
Because of the modular nature of mail handling, it is possible to use multiple
applications to process mail and accomplish more than simply deliver it.
Getting mail from the storage area and displaying it to the user is the purpose
of the MDA. MDA functionality can be found in some of the mail clients
(MUAs), which can cause some confusion to those still unfamiliar with the
concept of UNIX mail. As an example, the Procmail MDA provides filtering
based on rulesets; KMail and Evolution, both MUAs, provide filtering, but
the MUAs pine, mutt, and Balsa do not. Some MDAs perform simple
sorting, and other MDAs are designed to eliminate unwanted emails, such as
spam and viruses.
You would choose an MDA based on what you want to do with your mail.
This section presents several MDAs that offer functions you might find useful
in your particular situation. If you have simple needs (such as simply
organizing mail by rules), one of the MUAs that offers filtering might be
better for your needs. Ubuntu provides the Evolution MUA as the default
selection (and it contains some MDA functionality, as previously noted), so
try that first and see whether it meets your needs. If not, investigate one of the
following MDAs provided by Ubuntu.
Unless otherwise noted, all the MDA software discussed here is provided in
the Ubuntu repositories. Chapter 9, “Managing Software,” details the general
installation of any software.
Procmail
As a tool for advanced users, the Procmail application acts as a filter for email
as it is retrieved from a mail server. It uses rulesets (known as recipes) as it
reads each email message. No default configuration is provided; you must