Egress sources and pools in code

Define sources (one per outbound IP):

kumo.on('init', function()
  for i = 1, 8 do
    kumo.define_egress_source {
      name = 'ip-' .. i,
      source_address = '198.51.100.' .. (10 + i),
      ehlo_domain    = 'mail' .. i .. '.example.com',
    }
  end

  kumo.define_egress_pool {
    name = 'warming-pool',
    entries = {
      { name = 'ip-1', weight = 1 },
      { name = 'ip-2', weight = 1 },
      -- equal-weight rotation
    }
  }

  kumo.define_egress_pool {
    name = 'production-pool',
    entries = {
      { name = 'ip-3', weight = 5 },
      { name = 'ip-4', weight = 5 },
      { name = 'ip-5', weight = 3 },
    }
  }
end)

Select pool per-message:

kumo.on('get_queue_config', function(domain, tenant, campaign)
  local pool = 'production-pool'
  if tenant == 'new-customer' then pool = 'warming-pool' end
  return kumo.make_queue_config { egress_pool = pool }
end)

Enforce daily caps with the throttles module — a per-source message bucket reset at midnight. This is your warming enforcer.