diff --git a/src/configure.default b/src/configure.default
index d1ce2f1..1f10008 100644
--- a/src/configure.default
+++ b/src/configure.default
@@ -55,7 +55,7 @@
 # +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