Re: [exim] Using Exim as Backup Mail server

Mark wrote:
> I am interested in learning how to use an Exim server as a backup for
> multiple separate domains. My goal would be for the Exim server to
> receive mail for any of the domains when the primary for a domain is
> unavailable, and then automatically forward the received mail when the
> primary comes back up.
>
> Is there a tutorial on accomplishing this in terms of the necessary
> Exim configuration entries? Otherwaise, can someone give me some ideas
> on how to proceed?
>
> Thank you for your time,
>

Going from the default configuration file, you just have to define all
the domains you want to relay mail for in a domainlist like this:

domainlist relay_to_domains = domain1.tld : domain2.tld


Then configure a smarthost so that any mail received by your exim server
will be sent to your main server:
So as your fist router in the routers section:

smarthost:
driver = manualroute
domains = +relay_to_domains
transport = remote_smtp
route_list = * my.primary.server.tld
host_find_failed = defer
same_domain_copy_routing = yes
no_more