Fwd: Re: [NTLUG:Discuss] Sendmail question

[Eric Schnoebelen]

Joe Torma writes:
- Thank you Eric.  Here goes...

	Glad to be of service..

- > 	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?

	The fully qualified domain name (FQDN) is a name that
resolves on the public internet.  After all, the sending host is
going to need to be able to look up that name to deliver the
mail.

-                                                    Also, I am
- having trouble finding where to change the host name (currently
- localhost.localdomain) in the system.  Any pointers for RH 7.3?

	Someone else suggested /etc/sysconfig/network (or
something like that.) I don't have a running RH box, so I can't
offer any futher suggestions.

- > 	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.

	How much might the group be willing to spend to have
CGI and DB access, along with multiple forwarded addresses?
(contact me offline at eric at cirr.com -- I do web hosting, and
the occasional bit of virtual domain mail hosting)

- > 	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 the MX record has been updated)

	Yes.

- > - 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?

	Probably both. (not knowing how your network is setup, I
can't offer more guidance than that..)

- > 	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...

	I believe that RPM's exist for both QPOPPER and UW-IMAP.

--
Eric Schnoebelen		eric at cirr.com 		http://www.cirr.com
      "Memory is like an orgasm. It's a lot better if you don't
	  have to fake it." -Seymore Cray, on virtual memory