Constify pointers

diff --git a/src/src/receive.c b/src/src/receive.c
index 55dce21d3d48922f1b0d532b1524a566f0d5c821..50b2bf83c7c403ba139b914460c0af86d50573b2 100644 (file)
--- a/src/src/receive.c
+++ b/src/src/receive.c
@@ -1562,10 +1562,10 @@ BOOL date_header_exists = FALSE;
 
 /* Pointers to receive the addresses of headers whose contents we need. */
 
-header_line *from_header = NULL;
-header_line *subject_header = NULL;
-header_line *msgid_header = NULL;
-header_line *received_header;
+const header_line *from_header = NULL;
+const header_line *subject_header = NULL;
+const header_line *msgid_header = NULL;
+const header_line *received_header;
 
 #ifdef EXPERIMENTAL_DMARC
 int dmarc_up = 0;