diff -Naur spamass-milter-0.1.3a/spamass-milter.cpp spamass-milter-0.1.3a.gugu/spamass-milter.cpp
--- spamass-milter-0.1.3a/spamass-milter.cpp	2002-12-31 18:03:13.000000000 -0200
+++ spamass-milter-0.1.3a.gugu/spamass-milter.cpp	2003-01-07 10:30:53.000000000 -0200
@@ -80,6 +80,7 @@
 #include <signal.h>
 #include <poll.h>
 #include <errno.h>
+#include <arpa/inet.h>
 
 // C++ includes
 #include <cstdio>
@@ -88,6 +89,7 @@
 #include <string>
 #include <iostream>
 #include <fstream>
+#include <vector>
 
 #ifdef  __cplusplus
 extern "C" {
@@ -111,7 +113,7 @@
     "SpamAssassin", // filter name
     SMFI_VERSION,   // version code -- leave untouched
     SMFIF_ADDHDRS|SMFIF_CHGHDRS|SMFIF_CHGBODY,  // flags
-    NULL, // info filter callback
+    NULL, // connect info filter callback
     NULL, // HELO filter callback
     mlfi_envfrom, // envelope sender filter callback
     mlfi_envrcpt, // envelope recipient filter callback
@@ -123,7 +125,93 @@
     mlfi_close, // connection cleanup callback
   };
 
+static vector<string> accepted_domains;
+typedef pair<long,long> masked_ip;
+static vector<masked_ip> accepted_networks;
+
+static void tolower(string& s)
+{
+    for (int i=0; i < s.size(); ++i) {
+        s[i] = tolower(s[i]);
+    }
+}
+
+static void accept_relay(const char *relay_)
+{
+    string relay(relay_);
+    string::size_type noquad = relay.find_first_not_of("0123456789./");
+
+    if (noquad != string::npos) {       // domain name
+        tolower(relay);
+        accepted_domains.push_back(relay);
+    } else {
+        string::size_type slash  = relay.find_first_of('/');
+        unsigned long mask = 0xffffffff;
+        if (slash != string::npos) {    // net/mask
+            mask = inet_addr(relay.c_str() + slash + 1);
+            if (mask == INADDR_NONE) {
+                cerr << "error: Invalid netmask in relay spec (" << relay_ << ").";
+                exit(1);
+            }
+            relay.erase(slash);
+        }
+        unsigned long net = inet_addr(relay.c_str());
+        if (net == INADDR_NONE) {
+            cerr << "error: Invalid network in relay spec (" << relay_ << ").";
+            exit(1);
+        }
+
+        accepted_networks.push_back(make_pair(net&mask, mask));
+    }
+}
+
+static void dump_accepted_relays()
+{
+        for (vector<string>::iterator i = accepted_domains.begin();
+             i != accepted_domains.end(); ++i) {
+            debug(2, "accept_relay(%s)", i->c_str());
+        }
+        for (vector<masked_ip>::iterator i = accepted_networks.begin();
+             i != accepted_networks.end(); ++i) {
+            debug(2, "accept_relay(%08lx, %08lx)", ntohl(i->first), ntohl(i->second));
+        }
+}
+
+static bool is_accepted_relay(char *hostname, _SOCK_ADDR *hostaddr)
+{
+    if (hostname && accepted_domains.size()) {
+        string name(hostname);
+        tolower(name);
+        for (vector<string>::iterator i = accepted_domains.begin();
+             i != accepted_domains.end(); ++i) {
+            if (name.size() >= i->size()
+                && name.substr(name.size() - i->size(), i->size()) == *i) {
+                debug(3, "accept_relay(%s)", hostname);
+                return true;
+            }
+        }
+        debug(3, "dont accept_relay(%s)", hostname);
+    }
+
+    if (hostaddr
+        && hostaddr->sa_family == AF_INET
+        && accepted_networks.size()) {
+        unsigned long net = reinterpret_cast<struct sockaddr_in*>(hostaddr)->sin_addr.s_addr;
+        for (vector<masked_ip>::iterator i = accepted_networks.begin();
+             i != accepted_networks.end(); ++i) {
+            if ((net & i->second) == i->first) {
+                debug(3, "accept_relay(%08lx)", ntohl(net));
+                return true;
+            }
+        }
+        debug(3, "dont accept_relay(%08lx)", ntohl(net));
+    }
+
+    return false;
+}
+
 int flag_debug = 0;
+bool flag_accept=false;
 bool flag_reject = false;
 bool flag_sniffuser = false;
 int reject_score = -1;
@@ -136,7 +224,7 @@
 main(int argc, char* argv[])
 {
    int c, err = 0;
-   const char *args = "p:fd:mr:u:";
+   const char *args = "p:A:fd:mr:u:";
    char *sock = NULL;
    bool dofork = false;
 
@@ -146,6 +234,10 @@
 			case 'p':
 				sock = strdup(optarg);
 				break;
+			case 'A':
+				flag_accept = true;
+				accept_relay(optarg);
+				break;
 			case 'f':
 				dofork = true;
 				break;
@@ -172,8 +264,9 @@
    if (!sock || err) {
       cout << PACKAGE_NAME << " - Version " << PACKAGE_VERSION << endl;
       cout << "SpamAssassin Sendmail Milter Plugin" << endl;
-      cout << "Usage: spamass-milter -p socket [-d nn] [-f] [-m] [-r nn] [-u user]" << endl;
+      cout << "Usage: spamass-milter -p socket [-A relay] [-d nn] [-f] [-m] [-r nn] [-u user]" << endl;
       cout << "   -p socket: path to create socket" << endl;
+      cout << "   -A: accept relay by domain name or n.n.n.n/m.m.m.m network spec" << endl;
       cout << "   -d nn: set debug level to nn (1-3).  Logs to syslog" << endl;
       cout << "   -f: fork into background" << endl;
       cout << "   -m: don't modify body, Content-type: or Subject:" << endl;
@@ -203,6 +296,18 @@
 
    openlog("spamass-milter", LOG_PID, LOG_MAIL);
 
+   if (dontmodify) {
+       // Tell sendmail we won't change bodies so that it doesn't need
+       // to be prepared for that.
+       smfilter.xxfi_flags &= ~SMFIF_CHGBODY;
+   }
+
+   if (flag_accept) {
+       // Make sendmail call our connect callback if we need to.
+       smfilter.xxfi_connect = mlfi_connect;
+       dump_accepted_relays();
+   }
+
    (void) smfi_setconn(sock);
 	if (smfi_register(smfilter) == MI_FAILURE) {
 		fprintf(stderr, "smfi_register failed\n");
@@ -375,6 +480,25 @@
 // {{{ MLFI callbacks
 
 //
+// Gets called at the start of a SMTP connection
+//
+// checks if the messages in this connection should be accepted
+//
+sfsistat
+mlfi_connect(SMFICTX* ctx, char* hostname, _SOCK_ADDR *hostaddr)
+{
+    debug(1, "mlfi_connect: enter");
+
+    if (is_accepted_relay(hostname, hostaddr)) {
+        debug(1, "mlfi_connect: accept");
+        return SMFIS_ACCEPT;
+    } else {
+        debug(1, "mlfi_connect: continue");
+        return SMFIS_CONTINUE;
+    }
+}
+
+//
 // Gets called first for all messages
 //
 // creates SpamAssassin object and makes pointer to it
diff -Naur spamass-milter-0.1.3a/spamass-milter.h spamass-milter-0.1.3a.gugu/spamass-milter.h
--- spamass-milter-0.1.3a/spamass-milter.h	2002-12-23 15:08:30.000000000 -0200
+++ spamass-milter-0.1.3a.gugu/spamass-milter.h	2003-01-07 10:14:12.000000000 -0200
@@ -30,6 +30,7 @@
 
 string retrieve_field(const string&, const string&);
 
+sfsistat mlfi_connect(SMFICTX*, char*, _SOCK_ADDR *);
 sfsistat mlfi_envrcpt(SMFICTX*, char**);
 sfsistat mlfi_envfrom(SMFICTX*, char**);
 sfsistat mlfi_header(SMFICTX*, char*, char*);