-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
> An MX record is only necessary when an A record points to a machine
> that has no mail handler, and the MX record then points to an A record of
> a machine that does have a mail handler.
That's the other way around (I mean the reasoning): Empty MX list
is considered a special case when A record should be tried. You
should try to have a MX (even pointing at yourself, like
mail IN A 11.111.111.1111
mail IN MX 5 mail
) because it saves one DNS lookup.
> An MX record may not point to a C record even though it might
> seem to make sense to do so, simply because DNS was designed
> specifically prohibiting that.
It doesn't make that much sense:
1. One additional lookup.
2. Mail sent to CNAME should be "canonicized" - ie. the CNAMEs
in the addresses should be resolved. If MX points to CNAME, you
don't know if it should be canonicized or not.
Plus, of course, RFC says against that.
> Sending mail to a C record might seem to work, deceptively,
> because you may have included the A record in localhosts.
???
You can send mail directly to a host which is only a CNAME (and
the address gets rewritten to what CNAME really points at). In fact,
if you have CNAME and MX for the same host, the MX is ignored
(and probably considered an error).
> For example,
> if you have an A record stooges.com on a machine with QMail
> and stooge.com is in the /var/control/localhosts file
> then any mail sent to [EMAIL PROTECTED], moe.stooges.com,
> [EMAIL PROTECTED] will deliver if larry, moe, and curly
> are users.
If you meant [EMAIL PROTECTED], yes.
> If there is a C record three.stooges.com that aliases
> stooges.com (that's what a C record is) then
> [EMAIL PROTECTED], [EMAIL PROTECTED],
> [EMAIL PROTECTED] will also deliver because
> like a c programming macro three.stooges.com
> "becomes" stooges.com
Yes - I like that explanation :-)
> The deceptive part of that is this.
>
> If you want to route mail of [EMAIL PROTECTED]
> to go to curly@localhost you must creat an alias
> for shemp to route to curly and that will work for
> all localhosts.
>
> So there will be an effect that [EMAIL PROTECTED]
> will also go to the user curly.
>
> For explicit control of each domain, separately, you
> want to use virtual domains, not localhost.
Sure - all in "locals" are aliases for local host; ie. after you decided
the address in in aliases, only local part is used to route the mail. If
you want to use different handling for different domains, you want
virtual domains.
Caveat emptor: If three.stooges.com is a CNAME for stooges.com,
you are not too likely to receive a mail for
[EMAIL PROTECTED], since the CNAMEs should get
canonicized (rewritten), unless the other side is broken. If you want
virtual domain, you want MX pointing at you, not CNAME.
> Each virtualhost should have it's own A record.
> stooges.com has an A record
> three.stooges.com has an A record
> littlerascals.com has an A record
MX is enough. Although nothing prohibits it, you might (repeat:
might) have some problems with broken, brain-dead machines on
the other side that do a forward lookup, a reverse lookup, and then
seem surprised that they didn't get the original name. But hey,
yes, their behaviour would be broken.
> each is listed in rcpthosts
>
> and a virtual domain map is put into virtualdomains
> stooges.com:stooges
> three.stooges.com:threestooges
> littlerascals.com:littlerascals
>
> This way, there is one user for each
> virtual domain, and the .qmail routing
> in each of those is very specific.
> [EMAIL PROTECTED] can have a
> routing and [EMAIL PROTECTED]
> can properly bounce (since shemp
> was never a little rascal)
If I only knew what you're talking about - some TV show perhaps?
-----BEGIN PGP SIGNATURE-----
Version: PGP 6.0.2 -- QDPGP 2.60
Comment: http://community.wow.net/grt/qdpgp.html
iQA/AwUBN5bPEFMwP8g7qbw/EQLaPQCgguzZnoqORbewL2dTBP9/QjT1og0Aniqe
LPgVk8BL7n5GRwW3sbbK5+T8
=re9u
-----END PGP SIGNATURE-----
--
Petr Novotny, ANTEK CS
[EMAIL PROTECTED]
http://www.antek.cz
PGP key ID: 0x3BA9BC3F
-- Don't you know there ain't no devil there's just God when he's drunk.
[Tom Waits]
