diff --git a/src/configure.default b/src/configure.default
index 52e0536..3728043 100644
--- a/src/configure.default
+++ b/src/configure.default
@@ -54,7 +54,7 @@
# +local_domains, +relay_to_domains, and +relay_from_hosts, respectively. They
# are all colon-separated lists:
-domainlist local_domains = @
+domainlist local_domains = @ : localhost : localhost.localdomain
domainlist relay_to_domains =
hostlist relay_from_hosts = localhost
# (We rely upon hostname resolution working for localhost, because the default