my usual postfix front-end workflow is
postscreen
if 'fail', reject
if 'pass', then
internal smtp
etc
i'd like to implement a 'maintenance/offline mode' -- WITH smtp response --
effectively adding
postscreen
if 'fail', reject
if 'pass', then
+ if 'maintenance mode' = ON, then
+ reply SMTP 4XX, msg = (user specified message,
e.g. down 4 maintenance, try again in X hours)
+ else if 'maintenance mode' = OFF, then
internal smtp
etc
there are many paths to that particular mountain.
is there an already built-in maintenance-mode, or somesuch, in postfix?
it'd be most convenient; if it's in docs, i've missed it.
i thought about monkeying with stress-adaptive behavior, but that seems like a
bad rabbit-hole for this ...
