Authoritative guide to configuring Sendmail to use a relay for outgoing mail on FreeBSD?

[Polytropon]

On Tue, 12 Jan 2021 15:58:35 +0100, Peter Boosten via freebsd-questions wrote:
> Basically all my jails use another jail as mail hub:
> 
> Change /etc/mail/freebsd.submit.mc to reflect the correct mail hub
> 
> FEATURE(`msp', `[your.smart.host]', `MSA’)dnl
> 
> Also configure the confDOMAIN_NAME and confHELO_NAME to reflect your
> host/domain.
> 
> Then run ‘make install’. 
> 
> In my /etc/rc.conf there’s this:
> 
> sendmail_enable="NO"
> sendmail_msp_queue_enable="YES"
> sendmail_outbound_enable="NO"
> sendmail_submit_enable=“NO"
> 
> Then run ‘make restart’ in your /etc/mail directory.
> 
> This basically makes the machine not accept email from outside (only
> from the machine itself) and forwards everything to your smart host.

In the past, I have been using my ISP's mail relay until they
cut support for that. In order to have all outgoing messages
to be sent through the ISP's relay (instead of having my own
sendmail doing that, especially from behind a dynamic IP), I
had the followint setting in /etc/mail/`hostname`.mc:

	define(`SMART_HOST', `mx.example.com')

where mx.example.com is the mail relay I wanted to use, and
it worked for all systems from within the network of the ISP.
With a "make install", the setting was activated, and it worked
for many happy years. :-)




-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...