Re: [gentoo-user] Alternate Incoming Mail Server

[J. Roeleveld]

On 6 April 2020 14:35:04 CEST, Ashley Dixon <ash@××××××××××.uk> wrote:
>Hello,
>
>After many hours of confusing mixtures of pain and pleasure, I have a
>secure and
>well-behaved e-mail server which encompasses all the features I
>originally
>desired. However, in the event that I need to reboot the server
>(perhaps a
>kernel update was added to Portage), I would like to have a miniature
>mail
>server which catches incoming mail if, and only if, my primary server
>is down.
>
>I have Gentoo installation on an old Raspberry Pi (model B+), and was
>curious if
>such a set-up was possible ? I also want the solution to be as minimal
>as
>possible. I see the problem as three parts:
>
>(a) Convincing the D.N.S.\ and my router to redirect mail to the
>alternate
> server, should the default one not be reachable;
>
>(b) Creating the alternate mail server to be as lightweight as
>possible. I'm
>not even sure if I need an S.M.T.P.\ server (postfix). Would
>courier-imap do
> the trick on its own (with courier-authlib and mysql) ?
>
>(c) Moving mail from the alternate server to the main server once the
>latter
>has regained conciousness. I realise this is a slightly different
>problem, and
>is not even necessarily _required_ for operation, although it's
>certainly a
> nice-to-have.
>
>What do you think; is this at all possible ? Has anyone here done
>anything like
>this before ?
>
>Thanks in advance.

You'd need to install a SMTP server on the backup system and configure it to relay emails to your primary mailserver.

In the DNS you can configure priorities in the MX entries.

--
Joost
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.