Re: [exim] Server Upgrade

On Sat, Apr 13, 2019 at 06:15:33PM +0200, Rainer Dorsch via Exim-users 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.

The whole process is not so much about exim as farmore how the packet
management works.

(1) If you have your own configuration file in /etc/exim4/exim4.conf
there will be no such problem.

(2) If you have configured your Exim using the debian packet configuration
there also would be no problem.

(3) If you are running a modified configuration derived from the debian
configuration there might be a glitch but this would be unlikely.

> Can anybody recommend one of the approaches or even propose something
> better...?

- in case of (3) you also can:
- prevent exim from starting: set "exit 0" as first line in /etc/default/exim4
- create a packet filter rule dropping connections to port 25/tcp
- create /etc/exim4/exim4.conf which just makes exim return SMTP error 451

HTH

--
Christian Recktenwald
exim-users-dist@???