diff -urN src.orig/spam.c src/spam.c
--- src.orig/spam.c	Fri Jul 18 20:55:42 2008
+++ src/spam.c	Mon Nov 16 10:12:01 2009
@@ -48,6 +48,9 @@
 #endif
   uschar *spamd_address_work;
 
+  int try_count = 3;
+next_attempt:
+
   /* stop compiler warning */
   result = 0;
 
@@ -327,6 +330,11 @@
 
   /* reading done */
   (void)close(spamd_sock);
+
+  if ((spamd_buffer == NULL) || (spamd_buffer[0] == 0)) {
+    try_count--;
+    if (try_count > 0) goto next_attempt;
+  }
 
   /* dig in the spamd output and put the report in a multiline header, if requested */
   if( sscanf(CS spamd_buffer,"SPAMD/%7s 0 EX_OK\r\nContent-length: %*u\r\n\r\n%lf/%lf\r\n%n",