diff --git a/modules/mod_smtp_delivery_external.c b/modules/mod_smtp_delivery_external.c
index ebc04374..abf4b3f1 100644
--- a/modules/mod_smtp_delivery_external.c
+++ b/modules/mod_smtp_delivery_external.c
@@ -1940,6 +1940,10 @@ static int exists(struct smtp_session *smtp, struct smtp_response *resp, const c
 	UNUSED(user);
 	UNUSED(domain);
 
+	if (tolocal) {
+		return 0; /* We are not the right handler for local mail */
+	}
+
 	if (smtp_is_exempt_relay(smtp)) {
 		/* Allow an external host to relay messages for a domain if it's explicitly authorized to. */
 		bbs_debug(2, "%s is explicitly authorized to relay mail from %s\n", smtp_sender_ip(smtp), smtp_from_domain(smtp));
diff --git a/modules/mod_smtp_delivery_local.c b/modules/mod_smtp_delivery_local.c
index dce1c5ca..3d555b8b 100644
--- a/modules/mod_smtp_delivery_local.c
+++ b/modules/mod_smtp_delivery_local.c
@@ -50,15 +50,18 @@ static int exists(struct smtp_session *smtp, struct smtp_response *resp, const c
 	if (!mbox) {
 		return 0;
 	}
+
 	/* Mailbox exists, great! */
+
 	if (!fromlocal && minpriv_relay_in) {
+		/* Check if user is authorized to receive mail from external senders */
 		int userpriv = bbs_user_priv_from_userid((unsigned int) mailbox_id(mbox));
 		if (userpriv < minpriv_relay_in) {
 			smtp_abort(resp, 550, 5.1.1, "User unauthorized to receive external mail");
 			return -1;
 		}
 	}
-	/* It's a submission of outgoing mail, do no further validation here. */
+	/* If a a submission of outgoing mail, do no further validation here. */
 	return 1;
 }