diff --git a/roles/mail_server/templates/main.cf.j2 b/roles/mail_server/templates/main.cf.j2
index fe0dc478be41f85cdb772d105ed29ed556ace633..ad273cd8dd2de92d92cce6ce81a19bf093391f71 100644
--- a/roles/mail_server/templates/main.cf.j2
+++ b/roles/mail_server/templates/main.cf.j2
@@ -71,3 +71,7 @@ non_smtpd_milters = unix:/var/run/clamav/clamav-milter.ctl
 # Deliver undeliverable bounces to domain's postmaster. Helps with application
 # misconfigurations.
 notify_classes = resource, software, 2bounce
+
+# Fall-back to using native lookups (/etc/hosts etc) if DNS lookup fails. Useful
+# for local overrides of mail servers.
+smtp_host_lookup = dns, native