On 2019-04-13, Rainer Dorsch via Exim-users <[email protected]> wrote: > Hi, > > I want to upgrade my server from Debian Jessie to Debian Stretch. I am afraid > that at some time during the upgrade process, there is an invalid exim > configuration and messages get rejected. In order to avoid that I was > thinking > of either redirecting via DNS to a server which does not listen to port 25 to > enforce the sender to try again. Or redirect via DNS to a server which > buffers > all incoming messages until the Stretch setup is tested (not sure which > server > software does this though...). > > Can anybody recommend one of the approaches or even propose something > better...?
Use iptables rules to block the public allowing only your tests to reach exim. If you have not editied any Debian conffiles the upgrade should proceed smoothly with only a brief outage, no spurious rejects. during the upgrade process a bad config is much more likely to prevent exim from running than to cause spurious rejects. I use Debian's split config wich allows me to separate my config tweaks from the Debian provided conf files, this vastly reduces the amount of editing needed during upgrades. -- When I tried casting out nines I made a hash of it. -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
