Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Configuring a System
Setting Up Mail Services
Chapter 3274
Central Mail Hub A central mail hub (a mail server) receives e-mail
for its users and the users on the client computers that it serves. Users
either NFS-mount their incoming mail files to their local computers (the
clients), or log in to the hub to read their mail. Electronic mail can be
sent directly from the client computers.
Advantages:
✓ Only one computer needs to be connected to the
outside world, which protects (hides) the local
clients from the network outside, giving the
appearance that all mail from the workgroup is
coming from a central computer.
✓ Only one computer needs to run the sendmail
daemon (to “listen” for incoming e-mail).
✓ Data are centralized (easier to backup and control)
Disadvantages:
✓ Users of client machines must NFS-mount their
incoming mail files from the hub (or log in to the
hub) in order to read their mail.
✓ All electronic mail, even between client machines in
a local workgroup, must go through the hub
computer. This means that local mail traffic could
be slowed if the hub machine becomes overloaded;
and mail traffic would stop completely if the hub
goes down or becomes disconnected from the
network.
Gateway Mail Hub A gateway mail hub receives electronic mail for its
users and users of client computers that it serves. The hub forwards mail
intended for users of the client computers to those clients. Users do not
NFS-mount their incoming mail files to their local (client) computers;
they send and receive their mail directly from their own machines.
Advantages:
✓ Only one computer needs to be connected to the
outside world, which protects (hides) the local
clients from the network outside, giving the
appearance that all mail from the workgroup is
coming from a central computer.