--- qmail-smtpd.c.orig	2006-12-31 02:11:02.000000000 +0100
+++ qmail-smtpd.c	2006-12-31 02:35:31.000000000 +0100
@@ -44,6 +44,8 @@
 #define MAXHOPS 100
 unsigned int databytes = 0;
 unsigned int mfchk = 0;
+unsigned int greetdelay = 0;
+unsigned int drop_pre_greet = 0;
 int timeout = 1200;
 
 const char *protocol = "SMTP";
@@ -134,6 +136,7 @@
   out("451 See http://pobox.com/~djb/docs/smtplf.html.\r\n"); flush();
   eflush(); _exit(1);
 }
+void die_pre_greet() { out("554 SMTP protocol violation\r\n"); flush(); _exit(1); }
 
 void err_size() { out("552 sorry, that message size exceeds my databytes limit (#5.3.4)\r\n"); }
 void err_bmf() { out("553 sorry, your envelope sender has been denied (#5.7.1)\r\n"); }
@@ -282,6 +285,11 @@
   if (x) { scan_ulong(x,&u); databytes = u; }
   if (!(databytes + 1)) --databytes;
 
+  x = env_get("GREETDELAY");
+  if (x) { scan_ulong(x, &u); greetdelay = u; }
+  x = env_get("DROP_PRE_GREET");
+  if (x) { scan_ulong(x, &u); drop_pre_greet = u; }
+
   remoteip = env_get("TCPREMOTEIP");
   if (!remoteip) remoteip = "unknown";
   local = env_get("TCPLOCALHOST");
@@ -1308,12 +1316,40 @@
 int argc;
 char **argv;
 {
+  int n, m;
   childargs = argv + 1;
   sig_pipeignore();
   if (chdir(auto_qmail) == -1) die_control();
   setup();
   if (ipme_init() != 1) die_ipme();
   if (spp_connect()) {
+  if (!relayclient && greetdelay) {
+    if (drop_pre_greet) {
+      n = timeoutread(greetdelay ? greetdelay : 1, 0, ssinbuf, sizeof(ssinbuf));
+      if(n == -1) {
+        if (errno != error_timeout)
+          strerr_die3sys(1, "GREETDELAY from ", remoteip, ": ");
+      } else if (n == 0) {
+        strerr_die3x(1, "GREETDELAY from ", remoteip, ": client disconnected");
+      } else {
+        strerr_warn3("GREETDELAY from ", remoteip, ": client sent data before greeting", 0);
+        die_pre_greet();
+      }
+    }
+    else {
+      sleep(greetdelay);
+      m = 0;
+      for (;;) {
+        n = timeoutread(0, 0, ssinbuf, sizeof(ssinbuf));
+        if (n <= 0)
+          break;
+        if (n > 0 && m == 0) {
+          strerr_warn3("GREETDELAY from ", remoteip, ": client sent data before greeting. ignoring", 0);
+          m = 1;
+        }
+      }
+    }
+  }
   smtp_greet("220 ");
   out(" ESMTP\r\n");
   }