diff --git a/docs/rolereference.rst b/docs/rolereference.rst
index de9955ed759731be326f08b6ce2c119ca5517bb0..1da5c84f8192ea4249a444c778f0d144de0efdae 100644
--- a/docs/rolereference.rst
+++ b/docs/rolereference.rst
@@ -840,17 +840,17 @@ Postfix is configured as follows:
 Parameters
 ~~~~~~~~~~
 
-**local_mail_aliases** (dictionary, mandatory)
+**local_mail_aliases** (dictionary, optional, ``[]``)
   Dictionary defining the local aliases. Aliases defined this way will either be
   appended to default aliases on the server, or replace the existing entries (if
   the alias/recipient is already present). Keys in the dictionary are the local
   recipients/aliases, while the value provided should be a space-separated list
   of mail addresses (or local users) where the mails should be forwarded.
 
-**smtp_relay_host** (string, mandatory)
+**smtp_relay_host** (string, optional, ``None``)
   SMTP server via which the mails are sent out for non-local recipients.
 
-**smtp_relay_truststore** (string, mandatory)
+**smtp_relay_truststore** (string, optional, ``/etc/ssl/certs/truststore.pem``)
   Path to the file containing full X.509 CA certificate chain used for
   validating the server certificate presented by the relay server.
 
diff --git a/roles/mail_forwarder/defaults/main.yml b/roles/mail_forwarder/defaults/main.yml
new file mode 100644
index 0000000000000000000000000000000000000000..32713fcf5440cb8fbb22bf8e4ead2e18ac639774
--- /dev/null
+++ b/roles/mail_forwarder/defaults/main.yml
@@ -0,0 +1,5 @@
+---
+
+local_mail_aliases: []
+smtp_relay_host: ""
+smtp_relay_truststore: "/etc/ssl/certs/truststore.pem"
\ No newline at end of file