Marc Rietman wrote:
I'm fairly new to this list (didn't administer my own mailserver for a
few years) but have done a few qmail installations previously (nothing
comparable to most people on the list probably though). During my
education and after that in 'real life', I've always been told that
the priority in the DNS record is used to determine to which server to
send first. I've had a look at (what I believe is) the current RFC
document about DNS MX records, which can be found here:
ftp://ftp.rfc-editor.org/in-notes/rfc2821.txt. If I read it correctly
the priority number should be used to determine the order in which the
mailservers are to be tried.
Welcome to the list! Always nice to see a new face. Yes, the priority
number is supposed to be used to determine delivery preference.
I know that a RFC is only that (no obligations) and I know that
spammers sometimes (on purpose) use the lower priority MX record to
circumvent graylisting and so on. But in principle, the primary server
should have been used in the described situation (assuming there was
no connection error somewhere in between).
Could you tell me on what information your reply is based? Perhaps the
RFC I mentioned is superceded... I'm always willing to learn that I've
been taught incorrectly. It wouldn't be the first time it happened...
Kind regards,
My reply was based on experiences with my own servers and those that
I've worked on for other people/companies. The RFC is great and all but
as you said there are no obligations. When it comes down to it, we
follow the rules that the "biggies" such as AOL, Yahoo, Google,
Microsoft, etc. set. I have a couple domains that have 3 MX records and
I see mail delivered to all 3 machines regardless of priority or whether
or not the others are answering. As far as I know that particular RFC
has not been superceded but I'd say that roughly (without actually
creating some boiled down metrics) 70%-80% of the servers that send me
message actually follow that particular one. AOL has been seen
delivering to all 3 of my MX records regardless of machine status.
There's a couple other broadband companies that operate in the same
manner that I've seen.
---------------------------------------------------------------------
QmailToaster hosted by: VR Hosted <http://www.vr.org>
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
