diff --git a/internal/smtp/server.go b/internal/smtp/server.go
index 6bf24f7..26a3ec6 100644
--- a/internal/smtp/server.go
+++ b/internal/smtp/server.go
@@ -31,10 +31,11 @@ func NewServer(cancel context.CancelFunc, datastore store.Interface, submission
 	if submission {
 		out.handler = &Sender{}
 		out.server.Addr = ":587"
-		out.submission = true // Only allow login on submission ports
+		out.submission = true // Only allow login on the MSA Port
 	} else {
 		out.handler = &Receiver{}
 		out.server.Addr = ":25"
+		out.server.AuthDisabled = true // Don't allow login on the MTA port
 	}
 
 	return out