Fwd: Re: [NTLUG:Discuss] Sendmail question

Joe Torma joe.torma at sbcglobal.net
Mon Jun 3 18:18:01 CDT 2002


Thank you Eric.  Here goes...


> 	Some incorrect information needs to be corrected here.
>
> 	A DNS zone _must_ have only two records, the SOA, and
> the NS records.  An A record is not required, and frequently,
> not desired.
>
> 	For the case above, an MX record at the zone level is
> all that is required to route mail to the new server. However,
> the MX record _MUST_ contain the fully qualified domain name of
> the system that is going to accept the mail.  That system does
> not need to be in the same domain.  The MX record _must_not_
> contain an dotted-quad IP address (that is a violation of the
> DNS spec, and will cause some mail servers not to deliver to
> you.)

By fully qualified domain name, do you mean one recognised by internic or
 will an internal domain be sufficient?  Also, I am having trouble finding
 where to change the host name (currently localhost.localdomain) in the
 system.  Any pointers for RH 7.3?

> 	Since the DNS is probably hosted somewhere else, you'll
> need to have the DNS hosting company add the MX pointing at your
> server.

Easily accomplished. Thanks.

> 	FYI: it looks like richardsonhumanesociety.com already
> has two mail handlers defined...

Yes, through the hosting company who also sells mail services.  Currently all
mail to the domain is redirected to 1 email address as part ofthe $7. per
month hosting fee, which has been a great deal so far. The mail issue is
where it gets expensive.  It also costs more to add cgi or db access, all of
which would be very usefull, but expenses need to be contained for our all
volunteer non-profit group.

> 	In this case, sendmail is no easier or harder that
> postfix or qmail to configure.  In sendmail's case, add the new
> domain(s) to /etc/mail/sendmail.cw, or
> /etc/mail/local-host-names (depending upon the distribution) and
> restart sendmail.  Any mail destined for the hosts/domains listed in
> those files will be accepted for local delivery.

By domain names, do you mean simply adding richardsonhumanesociety.com
(presuming theMX record hasbeen updated)

> 	(it sounds like several people on this list have fallen
> for the myth that sendmail is hard to configure.  That hasn't
> been true for many a year... Having attempted to configure both
> sendmail and qmail, I find sendmail much easier.)

I operate under the presumption that leaders aren't leaders by accident (And
the Anti-MS crowd hissed...)  I have confidence in RH & sendmail's synergy
and would like to try that first.

> - You'll also need to know how to set up the necessary port forwarding
> - on your router.

Currently eth0 assigned dynamically, but always obtains the same IP which
never expires, set as DMZ through the router, so is fully exposed at this
time.  Will try to tighten that up later.

> 	Yes, you'll need to make sure the SMTP port is open on
> your firewall.

RE: My firewall, are we talking about the router or RH's internal firewall?

> 	True enough.  QPOPPER or UW-IMAP will play extremely
> well with the stock sendmail configurations, using mailboxes in
> /var/mail.  This _will_ require all your users to have accounts
> on the system, but you can give them a shell of /bin/false, or
> /bin/passwd, so they can't actually log in.

Here we have a whole nother issue (compiling, I believe, which I have never
attempted) I will ask numerous questions about later...  Thanks for all of
your help and patience.

Joe

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