diff -urN popa3d-0.6.4.1.orig/Makefile popa3d-0.6.4.1/Makefile
--- popa3d-0.6.4.1.orig/Makefile	Mon Nov 17 00:43:35 2003
+++ popa3d-0.6.4.1/Makefile	Sat Dec 25 10:52:22 2004
@@ -3,7 +3,7 @@
 RM = rm -f
 MKDIR = mkdir -p
 INSTALL = install -c
-CFLAGS = -Wall -O2 -fomit-frame-pointer
+CFLAGS = -Wall -O2 -fomit-frame-pointer -DPOPB4SMTP -DVALIDTIME=600
 # You may use OpenSSL's MD5 routines instead of the ones supplied here
 #CFLAGS += -DHAVE_OPENSSL
 LDFLAGS = -s
@@ -22,6 +22,8 @@
 #LIBS += -lnsl
 # OpenSSL (-DHAVE_OPENSSL)
 #LIBS += -lcrypto
+# Berkeley DB 4 - for POP-before-SMTP
+LIBS += -ldb-4.2
 
 DESTDIR =
 PREFIX = /usr/local
@@ -37,7 +39,7 @@
 	auth_passwd.o auth_shadow.o auth_pam.o \
 	pop_root.o pop_auth.o pop_trans.o \
 	protocol.o database.o mailbox.o \
-	misc.o \
+	misc.o pop_pbs.o \
 	md5/md5.o
 
 all: $(PROJ)
diff -urN popa3d-0.6.4.1.orig/README-POPB4SMTP popa3d-0.6.4.1/README-POPB4SMTP
--- popa3d-0.6.4.1.orig/README-POPB4SMTP	Thu Jan  1 00:00:00 1970
+++ popa3d-0.6.4.1/README-POPB4SMTP	Sat Dec 25 11:12:28 2004
@@ -0,0 +1,52 @@
+Code Monkeyboy <popa3d at paypc.com> has updated this patch from popa3d
+0.4 and Berkeley DB 1 to popa3d 0.6.4 and DB 4.  What follows is Garry's
+original README file for his popa3d 0.4 patch.
+
+	  popa3d patch for POP-before-SMTP and SMTP-after-POP
+
+		    Garry Glendown / Dec. 12th 2000
+
+On the 'net there are a couple of solutions to allow for POP-before-SMTP
+authentication in order to allow for relaying of mails. Anyway, the
+solutions I found didn't really apeal to me, so I hacked popa3d a bit,
+which we already used on one of our machines to serve mail to dialup
+customers.
+
+			     Prerequisites
+
+This patch supplies data to sendmail to allow for certain IPs to use it
+as a relaying host. In order to use with your sendmail installation, get
+the popauth-hack (http://www.sendmail.org/~ca/email/rules/popauth.m4)
+and install it by adding "HACK(`popauth')" to you .mc-file.
+
+			       Installing
+
+The patch - enabled through the POPB4SMTP-define in the Makefile -
+accesses the file "/etc/mail/popauth.db" (create with "makemap hash
+/etc/mail/popauth </dev/null") and adds the IP of the sucessfully
+authenticated POP-user to it. Once the IP appears in the .db-file,
+sendmail will allow the IP to relay mail from it.
+
+Apart from the IP, which is added as LHS in the database, the patch adds
+the timestamp of the authentication as RHS (which the sendmail-hack
+ignores). This timestamp is then used to remove old IPs which are older
+than VALIDTIME seconds (defined in the Makefile).
+
+			       Disclaimer
+
+This hack has been in production use for a week on our server and though
+there are in average 30-60 POP3 logins per minute (going up to 2-3
+requests per seconds during daytime), we have not had any problems.
+Please note that I'm no expert at the Berkeley db library - I just
+hacked up a version using the old db1 functions and it worked out.
+There may be things to do better, but it seems to work fine for me. If
+you have any suggestions, let me know ... I've tried to play it safe and
+wrapped all db-access into a semaphore-protected block, hopefully
+allowing for safe multiple execution ... also, I tried to make sure that
+the string functions all check for the available array length.
+
+If you have any suggestions, questions or feedback of any other kind
+concerning this hack, don't bug the author of popa3d, but drop me a mail
+at <garry at glendown.de>.
+
+G.Glendown / Dec 15th 2000
diff -urN popa3d-0.6.4.1.orig/pop_auth.c popa3d-0.6.4.1/pop_auth.c
--- popa3d-0.6.4.1.orig/pop_auth.c	Mon Sep  9 11:07:48 2002
+++ popa3d-0.6.4.1/pop_auth.c	Sat Dec 25 10:50:23 2004
@@ -14,6 +14,9 @@
 #if POP_VIRTUAL
 #include "virtual.h"
 #endif
+#ifdef POPB4SMTP
+char *client_addr(int fd);
+#endif
 
 static char *pop_user, *pop_pass;
 
@@ -75,15 +78,17 @@
 #if POP_VIRTUAL
 	if (virtual_domain) {
 		syslog(result == AUTH_OK ? SYSLOG_PRI_LO : SYSLOG_PRI_HI,
-			"Authentication %s for %s@%s",
+			"Authentication %s for %s@%s from %s",
 			result == AUTH_OK ? "passed" : "failed",
 			user ? user : "UNKNOWN USER",
-			virtual_domain);
+			virtual_domain,
+			client_addr(1) );
 		return;
 	}
 #endif
 	syslog(result == AUTH_OK ? SYSLOG_PRI_LO : SYSLOG_PRI_HI,
-		"Authentication %s for %s",
+		"Authentication %s for %s from %s",
 		result == AUTH_OK ? "passed" : "failed",
-		user ? user : "UNKNOWN USER");
+		user ? user : "UNKNOWN USER",
+		client_addr(1) );
 }
diff -urN popa3d-0.6.4.1.orig/pop_pbs.c popa3d-0.6.4.1/pop_pbs.c
--- popa3d-0.6.4.1.orig/pop_pbs.c	Thu Jan  1 00:00:00 1970
+++ popa3d-0.6.4.1/pop_pbs.c	Sat Dec 25 10:50:23 2004
@@ -0,0 +1,105 @@
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <string.h>
+
+char  addr_buf[256];
+char *client_addr(int fd)
+{
+        struct sockaddr sa;
+        struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
+        int     length = sizeof(sa);
+
+        strcpy(addr_buf,"0.0.0.0");
+
+        if (fd == -1) {
+                return addr_buf;
+        }
+
+        if (getpeername(fd, &sa, &length) < 0) {
+                return addr_buf;
+        }
+
+        strncpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr),64);
+
+        return addr_buf;
+}
+
+/*===========================================================================*/
+/* sem.c, Markus Franzke, 14-Feb-2000                                        */
+/* compressed Dec 2000 / G.Glendown                                          */
+/*===========================================================================*/
+ 
+#include <stdio.h>
+#include <errno.h>
+#include <sys/sem.h>
+#include <assert.h>
+
+/*---------------------------------------------------------------------------*/
+/*---------------------------------------------------------------------------*/
+int sem_attach(key_t sem_key) {
+
+	int sem_id = -1;
+  struct sembuf sem_ops[1];
+
+  sem_ops[0].sem_num = (short) 0;
+  sem_ops[0].sem_op = (short) 1;
+  sem_ops[0].sem_flg = 0;        /* NICHT: SEM_UNDO */
+
+  if ((sem_id = semget(sem_key, 1, IPC_CREAT|IPC_EXCL|0660)) >= 0) {
+    semop(sem_id, sem_ops, 1);
+  } else if (errno == EEXIST) {
+    sem_id = semget(sem_key, 0, 0);
+  }
+
+  return sem_id;
+
+}
+
+/*---------------------------------------------------------------------------*/
+/*---------------------------------------------------------------------------*/
+int sem_enter(int sem_id) {
+
+  struct sembuf sem_ops[1];
+
+  sem_ops[0].sem_num = (short) 0;
+  sem_ops[0].sem_op = (short) -1;
+  sem_ops[0].sem_flg = SEM_UNDO ;
+
+
+  while (semop(sem_id, sem_ops, 1) < 0) {
+    if (errno == EINTR) {
+      continue;
+    } else if (errno == EAGAIN) {
+			return 1;
+    } else {
+			return 2;
+    }
+  }
+
+	return 0;
+
+}
+
+/*---------------------------------------------------------------------------*/
+/*---------------------------------------------------------------------------*/
+void sem_leave(int sem_id) {
+
+  struct sembuf sem_ops[1];
+
+  sem_ops[0].sem_num = (short) 0;
+  sem_ops[0].sem_op = (short) 1;
+  sem_ops[0].sem_flg = SEM_UNDO;
+
+  while (semop(sem_id, sem_ops, 1) < 0) {
+		if (errno == EAGAIN) {
+			continue;
+    } else if (errno == EAGAIN) {
+      continue;
+		} else {
+			break;
+		}
+	}
+}
+
diff -urN popa3d-0.6.4.1.orig/pop_root.c popa3d-0.6.4.1/pop_root.c
--- popa3d-0.6.4.1.orig/pop_root.c	Thu Mar 21 20:15:19 2002
+++ popa3d-0.6.4.1/pop_root.c	Sat Dec 25 10:50:23 2004
@@ -25,6 +25,17 @@
 #include <sys/wait.h>
 #include <sys/types.h>
 
+#ifdef POPB4SMTP
+#include <fcntl.h>
+#include <db4/db_185.h>
+#include <time.h>
+#include <stdio.h>
+char * client_addr(int);
+int sem_attach(key_t sem_key) ;
+int sem_enter(int sem_id) ;
+void sem_leave(int sem_id) ;
+#endif
+
 #include "params.h"
 #include "protocol.h"
 #include "pop_auth.h"
@@ -108,6 +119,13 @@
 	static char auth[AUTH_BUFFER_SIZE + 2];
 	char *pass;
 	struct passwd *pw;
+#ifdef POPB4SMTP
+	DB *db;
+	DBT key,data;
+	char ts[16];
+	int ret,tv,sem;
+	char f2[256];
+#endif
 
 	known = 0;
 #if POP_VIRTUAL
@@ -154,6 +172,35 @@
 
 #if VIRTUAL_ONLY
 	if (!virtual_domain) return AUTH_FAILED;
+#endif
+
+#ifdef POPB4SMTP
+      sem=sem_attach(0x50413453);
+      sem_enter(sem);
+      db=dbopen("/etc/mail/popauth4.db",O_RDWR,0664,DB_HASH,0 );
+      key.data=client_addr(1);
+      key.size=strlen(key.data);
+      sprintf(ts,"%d",(int)time(0));
+      data.data=ts;
+      data.size=strlen(ts);
+      db->put(db,&key,&data,0);
+      db->sync(db,0);
+delete:
+      ret=db->seq(db,&key,&data,R_FIRST);
+      while (!ret) {
+              data.size=data.size<256?data.size:255;
+              strncpy(f2,data.data,data.size);
+              f2[data.size]=0;
+              tv=atoi(f2);
+              if ((tv+VALIDTIME)<time(0)) {
+                      db->del(db,&key,0);
+                      db->sync(db,0);
+                      goto delete;
+              }
+              ret=db->seq(db,&key,&data,R_NEXT);
+      }
+      db->close(db);
+      sem_leave(sem);
 #endif
 
 	if (set_user(pw)) return AUTH_FAILED;