minor tweaks to mail config comments

Author: bretton

sample-lightningTip.conf

@@ -68,13 +68,18 @@
 # LightningTip can send you a notification via email when you get a tip
 
 # Email address to which notifications get sent
-# If no mail address is set not notifications will be sent
+# If an email address is not set here, no notifications will be sent
+#
 # mail.email =
 
-# SMTP server with according port
+# SMTP server with corresponding port
 #
 # If no server is set LightningTip will try to send the mail with the command "mail"
-# That command will work only on Linux
+# (this command will work only on Linux with mail tools installed)
+#
+# Format is <hostname>:<port>, e.g.
+# mail.server = localhost:25
+# mail.server = remote.server.tld:465
 #
 # mail.server =