diff --git a/roles/mail_server/templates/main.cf.j2 b/roles/mail_server/templates/main.cf.j2
index 5c7b1d1a99fa7a86206508d6daedce1ec2591f8b..61180ecee06dc7661b4e8c6b20a45ffe6b8289e1 100644
--- a/roles/mail_server/templates/main.cf.j2
+++ b/roles/mail_server/templates/main.cf.j2
@@ -73,6 +73,11 @@ smtp_tls_security_level = may
 smtpd_relay_restrictions = permit_mynetworks
   reject_unauth_destination
 
+# Look-up for list of SASL login names that are allowed to send mails
+# using the passed-in sender address. Allow sending from both original
+# mailbox name _and_ associated aliases.
+smtpd_sender_login_maps = ldap:/etc/postfix/ldap-virtual-mailbox-maps.cf, ldap:/etc/postfix/ldap-virtual-alias-maps.cf
+
 # Reject delivery of mails for domains for which the local server is
 # not responsible, as well as any mails coming from addresses in one
 # of the configured RBL's.