On 6/24/2013 1:23 PM, Gilles Chehade wrote:
"relay backup" is used to setup secondary mail servers for a domain,
that is a server that accept mails for a domain and relay to MXs with
higher priority (i.e. lower preference in DNS).
So when you specify 'mx' as a parameter for the 'backup' keyword,
what does that mean precisely? A DNS server host name? A preference
value?
When I see MX, I think of the MX records in the DNS zone file. I
tried using a preference value, and that was rejected by smtpd as
invalid.
If the backup parameter is specified, the current server
will act as a backup server for the target domain.
Accepted mails are only relayed through servers with a
lower preference value in the MX record for the domain
than the one specified in mx. [...]
therefore:
accept for domain foobar.org relay backup mx2.example.org
will turn your machine as a backup mx for domain foobar.org with the
same priority as mx2.example.org, only relaying to other MXs that have
a higher priority
Excellent. That's precisely what I needed to know. Thank you!
Also, there is something in the smptd.conf(5) man page which I found
confusing. In the second example, it says "The mail server has an
external interface bnx0." But then the example code goes on to say
"listen on egress". Why is the interface 'bnx0' mentioned if it's not
actually used in the example code? I'm assuming that is a mistake, but I
don't know enough to say for certain.
Thanks again for this fantastic software. It pleases me to no end to
never have to look at a .mc file ever again.
