kumomta/docs/reference/kumo.dns/set_mx_timeout.md

kumo.dns.set_mx_timeout(DURATION)

{{since('2025.03.19-1d3f1f67')}}

Set overall time limit for MX record resolution. This applies to the MX record resolution, rather than the resolution of MX hosts into addresses.

DURATION is either a number expressed as optionally fractional seconds, or a human readable duration string like "5s" to specify the units.

The default value for this is "5 seconds".

!!! note This timeout is layered over any internal timeout that the underlying DNS resolver might be configured to use, which means that the effective timeout will be the smallest of both this value and what is configured for the underlying resolver.

kumo.on('pre_init', function()
  kumo.dns.set_mx_timeout(5)
  -- or alternatively: kumo.dns.set_mx_timeout("5s")
end)