On 8/12/21 09:37, Wietse Venema wrote:
Matt Corallo:
I tried variations of this but never could get it to work - as far as I could
tell the nexthop is fully resolved by the
time we get to the smtp daemon, so there aren't any relevant settings to
override or otherwise set the default on the
nexthop there.
In the FILTER command you specify transport AND nexthop. There is
nothing to be resolved BEFORE the SMTP client.
Ah, thanks. Sadly I'm not sure this solves the immediate issue either as it seems to override local domain delivery as
well. i.e. it results in any of the source addresses which would need proxying to external domains being proxied to
local domains as well.
For context, this doesn't feel like a crazy setup - some users have external addresses they want to be able to send mail
as, which we (obviously) need to relay via their external providers' smtp with authentication. For local-domain mails,
there are some providers (*cough* Microsoft *cough*) which treat all mail from low-volume IPs as spam, no matter what
best-practices you comply with, so we want to relay anything to Microsoft domains out via a third-party provider.
Its currently working with a second postfix instance and a simple socketmap program in transport_maps to lookup if a
domain's MX is *.outlook.com.
Matt
