On Mon Aug 14 2000 at 01:03, "Ed.Q.Bridges" wrote:
> On Mon, Aug 14, 2000 at 09:32:25AM +1000, Tony Nugent wrote:
> >
> > But do you *really* need sendmail running? You only need a mail
> > daemon listening on port 25 if you are a mail server accepting email
> > from elsewhere (usually via MX records in the DNS).
> excellent question!! and one that i've been wondering about.
> somewhere (and i don't remember where unfortunately), i thought
> i read (or, perhaps, mis-read) something that gave me the impression
> that the system needs sendmail to send error messages/syslog-style
> reports/etc to users on the local machine. so, with that (mis)impression
> in mind, i've always allowed sendmail to run.
Local client mailer programs should call sendmail directly for
outgoing email. /bin/mail does this, other programs (eg, exmh/nmh)
can do it via a utility called spost.
pop clients like fetchmail by default expect a mail daemon to be
running on the local system, but fetchmail (and others) should be
able to be configured to deliver POPed email into a file, directly
to /usr/{sbin,lib}/sendmail or directly to /usr/bin/procmail
> so, for a workstation (my home machine, and my desktop at work) i have
> sendmail in use. i would be more than happy to simply not start it
> at boot time as a daemon (but have the binary available on the system
> to use in scripts, etc). i read all my mail via a shell login to my
yes, exactly.
> isp's account (using telnet), or via pop3. would it be okay, on the
> abovementioned machines, to shut off sendmail as a daemon?
Yes, do this.
> we also have a server at work that i set up, that is a webserver, samba
> server, and database machine (will also be running a kannel server in
> the near future). that will be needing to send mail (from cgi-type
> scripts) as well. but, there will be no need to receive mail from
You don't need sendmail running as a daemon to send email from a
box, only to recieve it.
> the internet on it as well. again, i would prefer to shut off daemon
> use of sendmail, but have the binary available as a command line tool
> to send mail.
Turn it off, it will still work to send email out to the internet
(or, better, to a "smart relay host").
> i'd also appreciate a brief summary of *exactly* what sendmail does?
It is a mail transfer agent (MTA). It delivers email from a system,
and recieves email into a system when running as a daemon. And it
can do a lot of things with email, depending on how you configure
it. It is very powerful (but confusing for the uninitiated).
To go into more detail than this is a bit of a waste of time. Try
the sendmail site and FAQ at http://www.sendmail.org/ -- just about
everything I know about sendmail comes from information or pointers
at this site.
> where does it fit into the process of sending and receiving email?
It is the link between the internal mail system and the outside
world of the internet.
> also, are there any simpler to use/configure/manage MTA's out there
> that could be a suitable replacement?
Yes, qmail for one (which has a big following). But sendmail
(despite its history) is available everywhere, and it works as
documented. Like vi, my aim is to know it well, because everywhere
you go with unix, it is there :)
> thanks much!!
Cheers
Tony
