Index: src/acl.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/acl.c,v
retrieving revision 1.74
diff -u -r1.74 acl.c
--- src/acl.c	14 Feb 2007 15:33:40 -0000	1.74
+++ src/acl.c	20 Feb 2007 15:11:40 -0000
@@ -91,6 +91,7 @@
 #ifdef WITH_CONTENT_SCAN
        ACLC_REGEX,
 #endif
+       ACLC_REMOVE_HEADER,
        ACLC_SENDER_DOMAINS,
        ACLC_SENDERS,
        ACLC_SET,
@@ -153,6 +154,7 @@
 #ifdef WITH_CONTENT_SCAN
   US"regex",
 #endif
+  US"remove_header",
   US"sender_domains", US"senders", US"set",
 #ifdef WITH_CONTENT_SCAN
   US"spam",
@@ -277,6 +279,7 @@
 #ifdef WITH_CONTENT_SCAN
   TRUE,    /* regex */
 #endif
+  TRUE,    /* remove_header */
   FALSE,   /* sender_domains */
   FALSE,   /* senders */
   TRUE,    /* set */
@@ -337,6 +340,7 @@
 #ifdef WITH_CONTENT_SCAN
   FALSE,   /* regex */
 #endif
+  TRUE,    /* remove_header */
   FALSE,   /* sender_domains */
   FALSE,   /* senders */
   TRUE,    /* set */
@@ -496,6 +500,12 @@
     (1<<ACL_WHERE_MIME)),
   #endif
 
+  (unsigned int)
+  ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|       /* remove_header */
+    (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
+    (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
+    (1<<ACL_WHERE_NOTSMTP_START)),
+
   (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)|      /* sender_domains */
     (1<<ACL_WHERE_HELO)|
     (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
@@ -1029,6 +1039,20 @@
 
 
 
+static void
+setup_remove_header(uschar *hnames)
+{
+if (*hnames != 0)
+  {
+  if (acl_removed_headers == NULL)
+    acl_removed_headers = hnames;
+  else
+    acl_removed_headers = string_sprintf("%s : %s", acl_removed_headers, hnames);
+  }
+}
+
+
+
 
 /*************************************************
 *               Handle warnings                  *
@@ -3008,6 +3032,10 @@
     rc = regex(&arg);
     break;
     #endif
+
+    case ACLC_REMOVE_HEADER:
+    setup_remove_header(arg);
+    break;
 
     case ACLC_SENDER_DOMAINS:
       {
Index: src/globals.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/globals.c,v
retrieving revision 1.71
diff -u -r1.71 globals.c
--- src/globals.c	6 Feb 2007 12:19:27 -0000	1.71
+++ src/globals.c	20 Feb 2007 15:11:40 -0000
@@ -174,6 +174,7 @@
 uschar *acl_not_smtp_mime      = NULL;
 #endif
 uschar *acl_not_smtp_start     = NULL;
+uschar *acl_removed_headers    = NULL;
 uschar *acl_smtp_auth          = NULL;
 uschar *acl_smtp_connect       = NULL;
 uschar *acl_smtp_data          = NULL;
Index: src/globals.h
===================================================================
RCS file: /home/cvs/exim/exim-src/src/globals.h,v
retrieving revision 1.51
diff -u -r1.51 globals.h
--- src/globals.h	6 Feb 2007 12:19:27 -0000	1.51
+++ src/globals.h	20 Feb 2007 15:11:40 -0000
@@ -114,6 +114,7 @@
 extern uschar *acl_not_smtp_mime;      /* For MIME parts of ditto */
 #endif
 extern uschar *acl_not_smtp_start;     /* ACL run at the beginning of a non-SMTP session */
+extern uschar *acl_removed_headers;    /* Headers deleted by an ACL */
 extern uschar *acl_smtp_auth;          /* ACL run for AUTH */
 extern uschar *acl_smtp_connect;       /* ACL run on SMTP connection */
 extern uschar *acl_smtp_data;          /* ACL run after DATA received */
Index: src/smtp_in.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/smtp_in.c,v
retrieving revision 1.53
diff -u -r1.53 smtp_in.c
--- src/smtp_in.c	30 Jan 2007 11:45:20 -0000	1.53
+++ src/smtp_in.c	20 Feb 2007 15:11:40 -0000
@@ -898,6 +898,7 @@
 message_linecount = 0;
 message_size = -1;
 acl_added_headers = NULL;
+acl_removed_headers = NULL;
 queue_only_policy = FALSE;
 deliver_freeze = FALSE;                              /* Can be set by ACL */
 freeze_tell = freeze_tell_config;                    /* Can be set by ACL */
Index: src/receive.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/receive.c,v
retrieving revision 1.34
diff -u -r1.34 receive.c
--- src/receive.c	16 Feb 2007 22:23:35 -0000	1.34
+++ src/receive.c	20 Feb 2007 15:11:40 -0000
@@ -898,6 +898,41 @@
 {
 header_line *h, *next;
 header_line *last_received = NULL;
+int sep = ':';
+
+if (acl_removed_headers != NULL)
+  {
+  DEBUG(D_receive|D_acl) debug_printf(">>Headers deleted by %s ACL:\n", acl_name);
+
+  for (h = header_list; h != NULL; h = h->next)
+    {
+    int i;
+    uschar *list;
+    BOOL include_header;
+
+    if (h->type == htype_old) continue;
+
+    include_header = TRUE;
+    list = acl_removed_headers;
+
+    int sep = ':';         /* This is specified as a colon-separated list */
+    uschar *s;
+    uschar buffer[128];
+    while ((s = string_nextinlist(&list, &sep, buffer, sizeof(buffer)))
+            != NULL)
+      {
+      int len = Ustrlen(s);
+      if (header_testname(h, s, len, FALSE))
+	{
+	h->type = htype_old;
+        DEBUG(D_receive|D_acl) debug_printf("  %s", h->text);
+	}
+      }
+    }
+
+  acl_removed_headers = NULL;
+  DEBUG(D_receive|D_acl) debug_printf(">>\n");
+  }
 
 if (acl_added_headers == NULL) return;
 DEBUG(D_receive|D_acl) debug_printf(">>Headers added by %s ACL:\n", acl_name);