Re: [tlug] Mail server with Linux

["Jonathan Q" <jq@example.com>]

> sender.  With the RHL 8.0 test server I installed, sometimes the sender 
> address field is blank, or garbled.  Since there's no such problem with 
> the RHL 5.0 machine, I assume it's something about the RHL 8.0 machine.

Do you see anything unusual in the mail logs?

About this app, what language is it written in?  Does it do any re-writing
of the sender address, or is it just a simple pop3 client?

> the past couple of weeks.  I'd like to make sure that I'm building the 
> RHL 8.0 mail server correctly.  

Does this mean you built sendmail from source rather than using
the Red Hat binary?  If so, install the latest RH 8.0 package (which
you should already have; I don't believe it will let you not install an
MTA) and see if it works OK then.

> I followed the instructions in the book 
> I have carefully, but it's still an introductory book and I may be 
> missing something.

Can you tell us what, exactly, you did.  A copy of your sendmail.cf
wouldn't hurt.  Any sensitive information can be obfuscated.

> Sendmail.  For now I'd like to see what I can do with it.  I haven't 
> yet dished out the cash to get the Costales book -- maybe later.  A 
> "Sendmail for Dummies" would do for now.

AFAIK there isn' t one.  The bat book is *the* book to have on
Sendmail.  Note that there are also extensive docs available at
sendmail.org, and you probably have some in your RH install as well.
Look under /usr/share/doc.

> Point well taken.  Since the thing's behind our firewall, I trust that 
> it's still free from Cuckoo's eggs.

As Arnold would say, "Big mistake."  It seems to have at least an
outward-facing mail server, and there have been a number of root
exploits in sendmail since the RH 5.0 days.  What else does it serve
to the outside?  A website?  Apache has also had a few exploits, and
how secure are any CGI scripts?  If you have anything at all from
Matt's Script Archive, be afraid.  Be very afraid.  There was also
a remote root exploit in lpd. At the very least, run chkrootkit on that
box.  And of course, a default RH 5.0 install has a ton of ports open,
nothing firewalled on the box.  It may be behind your firewall, but
what's allowed through the firewall?  Better paranoid than sorry.

> distros someday.  Actually, the distro that's got me interested right 
> now is Plamo Linux 

Basically a localized Red Hat, IIRC.

Since you've been talking to Jack, you might want to try out Gentoo
on the old P133 box :-)

Jonathan