diff --git a/screening/dist/server/service.properties b/screening/dist/server/service.properties
index d9f5c523258d8e6b77043c427f35477287757cdd..039b52a96e3edfa5da979fb6e106c429ef549406 100644
--- a/screening/dist/server/service.properties
+++ b/screening/dist/server/service.properties
@@ -39,8 +39,10 @@ database-instance = HCS
 # SMTP properties used to send emails e.g. for library registration confirmations or error reporting
 # The current configuration saves the emails in the file system in the current '.' directory 
 mail.smtp.host = file://.
-#mail.smtp.host = localhost
-#mail.from = openbis-as@localhost
+# mail.smtp.host = localhost
+# mail.from = openbis-as@localhost
+# If empty user name and password are accepted, you have to uncomment these lines.
+# These lines can be commented only if SMPT server accepts any user name and password. 
 # mail.smtp.user = 
 # mail.smtp.password =