[Exim] best MX choice

I'm running Exim 4.12. One day I noticed that exim routes messages to MX
with higher value than it is set for this machine. For example:

I have domain example.net:
example.net mail is handled (pri=10) by relay1.example.net
example.net mail is handled (pri=25) by relay2.example.net
example.net mail is handled (pri=150) by relay3.example.net

relay2.example.net is machine where all happens.
If relay1.example.net is in retry database, exim routes all messages to
relay3.example.net, but it shouldn't do this, because relay2.example.net
have higher priority (lower MX value) than relay3.example.net.

Can I disable such behavior?

That's the config of dnslookup router:

dnslookup:
driver = dnslookup
domains = ! +local_domains
transport = remote_smtp
ignore_target_hosts = @[]

+local_domains contains relay2.example.net

--
Best wishes,
Dmitry Sergienko