diff -urN exim-4.69.orig/src/mytypes.h exim-4.69/src/mytypes.h
--- exim-4.69.orig/src/mytypes.h	2007-01-08 10:50:18.000000000 +0000
+++ exim-4.69/src/mytypes.h	2008-05-05 10:48:09.000000000 +0100
@@ -16,9 +16,17 @@
 #define MYTYPES_H
 
 
+#ifndef FALSE
 #define FALSE         0
+#endif
+
+#ifndef TRUE
 #define TRUE          1
+#endif
+
+#ifndef TRUE_UNSET
 #define TRUE_UNSET    2
+#endif
 
 
 /* If gcc is being used to compile Exim, we can use its facility for checking