[Wolves] Mail server program

[Ron Wellsted]

On Friday 07 Mar 2003 7:33 pm, Wayne Morris wrote:
> I want to use my webserver box to also act as a mailserver for my
> domain.

Welcome to the world of the BOFH.

> I've looked at a lot of write-ups for Sendmail, Qmail, Postfix etc and
> they all seem to be unintelligible jargon filled nonsense.

Postfix is probably the best/simplest bet, with webmin for the setup.  The 
main advantage is the config file is readable.  While sendmail is very 
powerful it is virtually impossible to read the config file.  (yes I know I 
used to sing the praises of sendmail, but I got fed up of having to re-edit 
the $*&^%** /etc/sendmail.cf file to make email work again every time there 
was an update...).  Postfix has several advantages: much simpler config file 
which is human readable, less frequet updates (oh, and the backing of a small 
computer company called IBM that people may have heard of...)

> Can someone recommend the easiest to set up and point me to the best
> tutorial to do it.

Try the LDP and the HOWTOs. See  
http://www.linux.org/docs/ldp/howto/Mail-Administrator-HOWTO.html

> The next thing I'm not sure about is configuring the outside world to
> talk to my box.
>
> No-ip will forward mail.domain.co.uk , www.domain.co.uk to my cable
> modem ip address.
>
> Does this also mean that email to foo@domain.co.uk will also be routed
> to me or do I have to do anything else? Where do MX records come into
> all this?

First of all, check the server is not an "open relay".  Basically this means 
that either endpoint (the "From:" or "To:" address) should include your 
domain.  It MUST NOT allow "From: spammer@spam.com To: victim@victim.org".
My party-piece is to telnet into the server on port 25 and talk smtp with the 
above addresses.  The response should be "relaying denied" with matching log 
entry.  Ideally the server should also silently discard any "From:" domains 
that it cannot resolve in DNS, as this can eliminate quite a bit of spam.

The MX records define the Mail eXchangers for a domain.  A standards compliant 
mail server will connect to the highest priority MX (lowest no.) first then 
the next etc.  The idea is that the lower priority servers will "store and 
forward" if the highest (real) MX server is offline for any reason (mini rant 
because of broken servers that only try the highest priority MX server then 
give up (try yahoo webmail (unless they fixed it))).  So every domain 
must/should have at least 1 MX record which resolves to a real mail server.

Also the addresses abuse@domain.co.uk and postmaster@domain.co.uk must be 
aliased to reach real people (certain ISPs should RTFRFCs).

Personally my domains are setup to forward to my various mailboxes which I 
then pickup with fetchmail every 30 mins.  This method has the advantage of 
not having to open a hole in my firewall.  I stil run Postfix for internal 
mail distribution and outgoing mail.

(and lusers wonder why BOFHs exist...)

-- 
Ron Wellsted
http://www.wellsted.org.uk
mailto:ron@wellsted.org.uk