On Tue, Apr 10, 2001 at 03:38:09AM +0200, Boris wrote:
> Tuesday, April 10, 2001, 12:16:31 AM, you wrote:
> TL> On Mon, Apr 09, 2001 at 02:33:45AM -0600, Kashan Sadiq wrote:
> >> If there are two servers running qmail on both of them. One is
> >> primary and the second is backup mail server which is for use of Queueing
> >> only. Now how would the mails on secondary mail server transfer to primary
> >> mail server and then stores in user accounts automatically.
>
> TL> 2. On the backup mail server, put the domain names you will accept
> TL> mail for in the .../qmail/control/rcpthosts file.
>
> The topic "backup mailserver" is very interesting. The external SMTP
> Server delivers automatically to ALL MX Servers of a domain? It would
> be interesting to know.
I'm not entirely sure what you're asking, but I'll try to answer this.
Specifically, I don't know what you mean by "external SMTP Server".
Assume you have two mail servers smtp1.example.com and
smtp2.example.com. Assume further that the DNS contains two MX records
for example.com, with smtp1.example.com assigned a priority (or
distance) of 10 and smtp2.example.com assigned a priority of 20.
A mail transfer agent (MTA) will attempt to deliver mail to the MX with
the smaller priority. If that server is unavailable, for whatever
reason, it will try to deliver to an MX with a larger priority. In my
example, if smtp1 is unavailable, the MTA will attempt to deliver to
smtp2. If it suceeds, it's finished. It will not deliver to more than
one MX.
smtp2, if configured to be a "backup" only, will attempt to deliver to
smtp1 (the higher priority, lower numbered MX). Assuming smtp1 becomes
available again, the mail will be delivered by smtp2 to smtp1. Once it's
delivered, smtp2 is finished. smtp1 is now responsible for getting the
mail to the user.
This is pretty basic Internet mail stuff...
Tim
(btw, no need to CC me. I read the list.)
