Re: tlug: Re: A myriad of mailers

[Rex Walters <rex@example.com>]

>>>>> Howard Abbey writes:  (on 11 Mar 99)

> So, on a site not well administered (my personal one, which will
> have a full time net connection in the fall for the first time),
> which is the safer option in people's opinion.  Sendmail configured
> by a distributor with current updates, or qmail (distributor configured,
> if that's available), or postfix, or whatever.

Personal taste time, for sure.  Full time connection increases your
exposure, but you need to do your own risks analysis.  Me, I don't worry
too much about people hacking my personal machine (not much of interest
on it, and not much of a vicarious thrill in crashing/thrashing a
machine with only one user, of course, if I've *really* pissed someone
off recently .... :-).

The simplest answer is to strip out every unneeded network service
*including* smtp.  If you POP/IMAP down all your mail from your
provider there is no reason you have to run a smtpd at all.  Just use
sendmail to send outgoing mail and don't run it as a daemon (the "-bd"
option iirc).  Your MUA likely fires up a new instance of sendmail each
time it sends a mail message anyway (rather than speaking SMTP to a port
directly).  If you don't listen on port 25, nobody can attack you on it.

Only problem (minor) is if you use fetchmail to retrieve your mail.  By
default it delivers to the SMTP port.  I believe it can be configured to
deliver to a sendmail process (or qmail-inject, for that matter).
Though I've never tried it myself.

When I get my full-time DSL connection (just a dream at the moment,
sigh) I'll probably do a draconian purge of inetd.conf, and only allow
incoming ssh.  I will want to allow incoming SMTP though, and I'm more
than comfortable letting qmail do the job for me (which I can't say
about sendmail).  Partly personal biases, partly training/familiarity
(haven't mucked with sendmail in a long time, haven't mucked with
postfix/exim/whatever at all), mostly due to design decisions and brief
perusal of the code.  I'd encourage you to read the FAQ, INTERNALS, and
SECURITY documents that come with the qmail distribution, as well as
documents on djb's web site to form your own opinion.

Regards,
-- 
Rex
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