if you want to do that globally, and not just per-domain, you might try this: I’m not totally sure this will work for the default and we don’t show an example of this otherwise
[default.sources."ip-1"]
skip_hosts = ["::/0"]
[default.sources."ip-2"]
skip_hosts = ["0.0.0.0/0"] # I didn't test this, but a v4 cidr should work here
yeah i will try that
the only issue i have is say the destination has only ipv4 addresses and gets assigned to ip-2 in round robin
would it just fail because all of the MX’s are caught by skip hosts
it’ll experience a transient failure, yeah. It’s “no different” than trying to assign an IPv4 address that isn’t plumbed properly
it would definitely be less of a headache to just use IPv4 :-p
ha
i’m a masochist, what can i say
There isn’t an especially good story around IPv6 address reputation for anti-abuse purposes, TBH, so you might find that you’re better off from an overall deliverability standpoint
i went to all the work to get us fully operational on dual-stack, i’m going to use it dammit
really the only mbp we have trouble with ipv6 is google workspace
the majority of our email gets delivered to o365 and it works same-same
but we’ve been delivering v6 for maybe 1.5 years now on the same ips
what I’d suggest is that you do some custom lua to use a combination of lookup_mx - KumoMTA Docs and lookup_addr - KumoMTA Docs at reception time to see if the MX is v6 capable, then use that information to drive your pool selection for that domain
for now though i might turn it off just so that i dont have a bunch of messages in the queue lagging in retryville
is there a way to suspend a source with messages currently in the queue? i’ve only ever changed the config but if a message is in flight it will throw errors in the log
you can suspend a source+destination by its site_name using kcli suspend-ready-q - KumoMTA Docs
you cannot blanket suspend a source
@free-spirited-yorksh @faithful-ostrich i changed ip-2 to a v4 source and configured the local dns server to filter out all AAAA and now it’s humming along 
will probably pull v6 out of our egress sources for now just to get up and going