diff -ru courier-imap-4.0.1/imap/pop3d.dist.in courier-imap-4.0.1-apop/imap/pop3d.dist.in
--- courier-imap-4.0.1/imap/pop3d.dist.in	2004-10-31 00:39:57.000000000 +0900
+++ courier-imap-4.0.1-apop/imap/pop3d.dist.in	2005-01-09 19:43:02.000000000 +0900
@@ -119,3 +119,9 @@
 # MAILDIRPATH - directory name of the maildir directory.
 #
 MAILDIRPATH=Maildir
+
+##NAME: POP3DHOSTNAME:0
+#
+# POP3DHOSTNAME - APOP time-stamp hostname.
+#
+POP3DHOSTNAME=localhost.localdomain
diff -ru courier-imap-4.0.1/imap/pop3login.c courier-imap-4.0.1-apop/imap/pop3login.c
--- courier-imap-4.0.1/imap/pop3login.c	2005-01-05 11:31:36.000000000 +0900
+++ courier-imap-4.0.1-apop/imap/pop3login.c	2005-01-09 19:44:50.000000000 +0900
@@ -14,6 +14,7 @@
 #include	<signal.h>
 #include	<ctype.h>
 #include	<fcntl.h>
+#include	<time.h>
 #if	HAVE_UNISTD_H
 #include	<unistd.h>
 #endif
@@ -26,6 +27,7 @@
 #include	<courierauthdebug.h>
 #include	<courierauthsasl.h>
 #include	"tcpd/spipe.h"
+#include	"md5/md5.h"
 
 static const char rcsid[]="$Id: courier-imap-4.0.1-apop.patch 2 2005-12-30 14:34:29Z setoppu $";
 
@@ -242,12 +244,15 @@
 int main(int argc, char **argv)
 {
 char	*user=0;
-char	*p;
+char	*p,*r=0;
 char	buf[BUFSIZ];
-int	c;
+int	c,j;
 const	char *ip=getenv("TCPREMOTEIP");
 char authservice[40];
 char *q ;
+time_t	now;
+char	*okmesg=0;
+char	*hostname=getenv("POP3DHOSTNAME");
 
 	if (!ip || !*ip)
 	{
@@ -264,10 +269,27 @@
 	pop3d=argv[1];
 	defaultmaildir=argv[2];
 
+	if(hostname == NULL || *hostname == '\0')
+	{
+		fprintf(stderr, "INFO: Hostname is not setup, A default Hostname is used,\n");
+		fflush(stderr);
+		hostname="localhost.localdomain";
+	}
+
 	courier_authdebug_login_init();
 
+	time(&now);
 	fprintf(stderr, "DEBUG: Connection, ip=[%s]\n", ip);
-	printf("+OK Hello there.\r\n");
+	j=strlen(hostname)+26;
+	if ((okmesg=malloc(j)) == 0)
+	{
+		printf("-ERR Server out of memory, aborting connection.\r\n");
+		fflush(stdout);
+		perror("malloc");
+		exit(1);
+	}
+	snprintf(okmesg, j, "<%lu.%lu@%s>", (unsigned long)(getpid() & 0xffffffff), (unsigned long)(now & 0xffffffff), hostname);
+	printf("+OK Hello there. %s\r\n", okmesg);
 
 	fflush(stdout);
 	fflush(stderr);
@@ -433,12 +455,65 @@
 				printf("-ERR Login failed.\r\n");
 				fflush(stdout);
 				continue;
+
+			} else if (strcmp(p, "APOP") == 0)
+			{
+				int rc;
+
+				p=strtok(0, " \t\r");
+				if (p)
+				{
+					if (user) free(user);
+					if ((user=malloc(strlen(p)+1)) == 0)
+					{
+						printf("-ERR Server out of memory, aborting connection.\r\n");
+						fflush(stdout);
+						perror("malloc");
+						exit(1);
+					}
+					strcpy(user, p);
+				}
+				p=strtok(0, "\t\r");
+				if (p == 0)
+				{
+					printf("-ERR APOP required.\r\n");
+					fflush(stdout);
+					continue;
+				}
+				if ((r=malloc(strlen(p)+strlen(okmesg)+3)) == 0)
+				{
+					printf("-ERR Server out of memory, aborting connection.\r\n");
+					fflush(stdout);
+					perror("malloc");
+					exit(1);
+				}
+				strcat(strcat(strcat(strcpy(r, p), " "), okmesg), "\t");
+				q="apop";
+				rc=auth_login(q, user, r, login_callback, NULL);
+				free(r);
+				r=0;
+				courier_safe_printf("INFO: LOGIN "
+					"FAILED, user=%s, ip=[%s]",
+					user, ip);
+				if (rc > 0)
+				{
+					perror("ERR: authentication error");
+					printf("-ERR Temporary problem, please try again later\r\n");
+					fflush(stdout);
+					exit(1);
+				}
+				sleep(5);
+				printf("-ERR Login failed.\r\n");
+				fflush(stdout);
+				continue;
 			}
 		}
 		printf("-ERR Invalid command.\r\n");
 		fflush(stdout);
 	}
 	fprintf(stderr, "DEBUG: Disconnected, ip=[%s]\n", ip);
+	free(okmesg);
+	if (r) free(r);
 	exit(0);
 	return (0);
 }