qregex-20060423.patch

Changelog

2006 04 23

qregex adds the matched regex pattern to its log entries if the LOGREGEX

environment variable is set.

2004 07 25

Added the badmailfromnorelay and badmailtonorelay control files.

Surrounded addresses in log messages with '<' and '>' to make picking them

out of log files with scripts easier.

2004 06 01

Updated README.qregex.

2004 03 17

Added the badhelo control file. This allows qregex to do pattern matching

againt the HELO host name presented by the smtp client.

Plugged a memory leak. The two stralloc structures in the bmcheck function in

qmail-smtpd have been made static. This prevents the structures from

allocating new memory every time the bmcheck function is called.

2004 02 07

qregex now ignores empty envelope senders ('mail from' command). Empty envelope

senders will not be compared to any regular expressions in the badmailfrom

control file and will always be accepted by qregex. Prior to this version it

was possible to write regular expressions that would reject mail with empty

envelope senders.

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/hier.c ./netqmail-1.05/netqmail-1.05/hier.c

--- ./netqmail-1.05.orig/netqmail-1.05/hier.c	1998-06-15 06:53:16.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/hier.c	2006-04-22 21:45:16.106777997 -0400

@@ -76,6 +76,7 @@

   c(auto_qmail,"boot","binm3+df",auto_uido,auto_gidq,0755);

   c(auto_qmail,"doc","FAQ",auto_uido,auto_gidq,0644);

+  c(auto_qmail,"doc","README.qregex",auto_uido,auto_gidq,0644);

   c(auto_qmail,"doc","UPGRADE",auto_uido,auto_gidq,0644);

   c(auto_qmail,"doc","SENDMAIL",auto_uido,auto_gidq,0644);

   c(auto_qmail,"doc","INSTALL",auto_uido,auto_gidq,0644);

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/install-big.c ./netqmail-1.05/netqmail-1.05/install-big.c

--- ./netqmail-1.05.orig/netqmail-1.05/install-big.c	1998-06-15 06:53:16.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/install-big.c	2006-04-22 21:45:16.107777820 -0400

@@ -76,6 +76,7 @@

   c(auto_qmail,"boot","binm3+df",auto_uido,auto_gidq,0755);

   c(auto_qmail,"doc","FAQ",auto_uido,auto_gidq,0644);

+  c(auto_qmail,"doc","README.qregex",auto_uido,auto_gidq,0644);

   c(auto_qmail,"doc","UPGRADE",auto_uido,auto_gidq,0644);

   c(auto_qmail,"doc","SENDMAIL",auto_uido,auto_gidq,0644);

   c(auto_qmail,"doc","INSTALL",auto_uido,auto_gidq,0644);

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/Makefile ./netqmail-1.05/netqmail-1.05/Makefile

--- ./netqmail-1.05.orig/netqmail-1.05/Makefile	2004-06-04 21:51:58.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/Makefile	2006-04-22 21:45:16.109777466 -0400

@@ -1532,16 +1532,16 @@

 	./compile qmail-showctl.c

 qmail-smtpd: \

-load qmail-smtpd.o rcpthosts.o commands.o timeoutread.o \

+load qmail-smtpd.o rcpthosts.o qregex.o commands.o timeoutread.o \

 timeoutwrite.o ip.o ipme.o ipalloc.o control.o constmap.o received.o \

 date822fmt.o now.o qmail.o cdb.a fd.a wait.a datetime.a getln.a \

-open.a sig.a case.a env.a stralloc.a alloc.a substdio.a error.a str.a \

+open.a sig.a case.a env.a stralloc.a alloc.a strerr.a substdio.a error.a str.a \

 fs.a auto_qmail.o socket.lib

-	./load qmail-smtpd rcpthosts.o commands.o timeoutread.o \

+	./load qmail-smtpd qregex.o rcpthosts.o commands.o timeoutread.o \

 	timeoutwrite.o ip.o ipme.o ipalloc.o control.o constmap.o \

 	received.o date822fmt.o now.o qmail.o cdb.a fd.a wait.a \

 	datetime.a getln.a open.a sig.a case.a env.a stralloc.a \

-	alloc.a substdio.a error.a str.a fs.a auto_qmail.o  `cat \

+	alloc.a strerr.a substdio.a error.a str.a fs.a auto_qmail.o  `cat \

 	socket.lib`

 qmail-smtpd.0: \

@@ -1681,6 +1681,10 @@

 constmap.h stralloc.h gen_alloc.h rcpthosts.h

 	./compile rcpthosts.c

+qregex.o: \

+compile qregex.c qregex.h

+	./compile qregex.c

+

 readsubdir.o: \

 compile readsubdir.c readsubdir.h direntry.h fmt.h scan.h str.h \

 auto_split.h

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/qmail-control.9 ./netqmail-1.05/netqmail-1.05/qmail-control.9

--- ./netqmail-1.05.orig/netqmail-1.05/qmail-control.9	1998-06-15 06:53:16.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/qmail-control.9	2006-04-22 21:45:16.109777466 -0400

@@ -20,7 +20,11 @@

 Comments are allowed

 in

+.IR badhelo ,

 .IR badmailfrom ,

+.IR badmailfromnorelay ,

+.IR badmailto ,

+.IR badmailtonorelay ,

 .IR locals ,

 .IR percenthack ,

 .IR qmqpservers ,

@@ -40,7 +44,11 @@

 .ta 5c 10c

 control	default	used by

+.I badhelo	\fR(none)	\fRqmail-smtpd

 .I badmailfrom	\fR(none)	\fRqmail-smtpd

+.I badmailfromnorelay	\fR(none)	\fRqmail-smtpd

+.I badmailto	\fR(none)	\fRqmail-smtpd

+.I badmailtonorelay	\fR(none)	\fRqmail-smtpd

 .I bouncefrom	\fRMAILER-DAEMON	\fRqmail-send

 .I bouncehost	\fIme	\fRqmail-send

 .I concurrencylocal	\fR10	\fRqmail-send

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/qmail-showctl.c ./netqmail-1.05/netqmail-1.05/qmail-showctl.c

--- ./netqmail-1.05.orig/netqmail-1.05/qmail-showctl.c	1998-06-15 06:53:16.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/qmail-showctl.c	2006-04-22 21:45:16.110777288 -0400

@@ -214,7 +214,11 @@

     _exit(111);

   }

-  do_lst("badmailfrom","Any MAIL FROM is allowed.",""," not accepted in MAIL FROM.");

+  do_lst("badhelo","Any HELO host name is allowed.",""," HELO host name denied if it matches this pattern.");

+  do_lst("badmailfrom","Any MAIL FROM is allowed.",""," MAIL FROM denied if it matches this pattern.");

+  do_lst("badmailfromnorelay","Any MAIL FROM is allowed.",""," MAIL FROM denied if it matches this pattern and RELAYCLIENT is not set.");

+  do_lst("badmailto","No RCPT TO are specifically denied.",""," RCPT TO denied if it matches this pattern.");

+  do_lst("badmailtonorelay","No RCPT TO are specifically denied.",""," RCPT TO denied if it matches this pattern and RELAYCLIENT is not set.");

   do_str("bouncefrom",0,"MAILER-DAEMON","Bounce user name is ");

   do_str("bouncehost",1,"bouncehost","Bounce host name is ");

   do_int("concurrencylocal","10","Local concurrency is ","");

@@ -267,7 +271,11 @@

     if (str_equal(d->d_name,"..")) continue;

     if (str_equal(d->d_name,"bouncefrom")) continue;

     if (str_equal(d->d_name,"bouncehost")) continue;

+    if (str_equal(d->d_name,"badhelo")) continue;

     if (str_equal(d->d_name,"badmailfrom")) continue;

+    if (str_equal(d->d_name,"badmailfromnorelay")) continue;

+    if (str_equal(d->d_name,"badmailto")) continue;

+    if (str_equal(d->d_name,"badmailtonorelay")) continue;

     if (str_equal(d->d_name,"bouncefrom")) continue;

     if (str_equal(d->d_name,"bouncehost")) continue;

     if (str_equal(d->d_name,"concurrencylocal")) continue;

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/qmail-smtpd.8 ./netqmail-1.05/netqmail-1.05/qmail-smtpd.8

--- ./netqmail-1.05.orig/netqmail-1.05/qmail-smtpd.8	1998-06-15 06:53:16.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/qmail-smtpd.8	2006-04-22 21:45:16.110777288 -0400

@@ -37,11 +37,26 @@

 even though such messages violate the SMTP protocol.

 .SH "CONTROL FILES"

 .TP 5

+.I badhelo

+Unacceptable HELO/EHLO host names.

+.B qmail-smtpd

+will reject every recipient address for a message if

+the host name is listed in, 

+or matches a POSIX regular expression pattern listed in,

+.IR badhelo .

+If the 

+.B NOBADHELO 

+environment variable is set, then the contents of 

+.IR badhelo 

+will be ignored.

+For more information, please have a look at doc/README.qregex.

+.TP 5

 .I badmailfrom

 Unacceptable envelope sender addresses.

 .B qmail-smtpd

 will reject every recipient address for a message

-if the envelope sender address is listed in

+if the envelope sender address is listed in, or matches a POSIX regular expression

+pattern listed in,

 .IR badmailfrom .

 A line in

 .I badmailfrom

@@ -49,6 +64,32 @@

 .BR @\fIhost ,

 meaning every address at

 .IR host .

+For more information, please have a look at doc/README.qregex.

+.TP 5

+.I badmailfromnorelay

+Functions the same as the

+.IR badmailfrom

+control file but is read only if the 

+.B RELAYCLIENT 

+environment variable is not set.

+For more information, please have a look at doc/README.qregex.

+.TP 5

+.I badmailto

+Unacceptable envelope recipient addresses.

+.B qmail-smtpd

+will reject every recipient address for a message if the recipient address

+is listed in,

+or matches a POSIX regular expression pattern listed in,

+.IR badmailto .

+For more information, please have a look at doc/README.qregex.

+.TP 5

+.I badmailtonorelay

+Functions the same as the

+.IR badmailto

+control file but is read only if the

+.B RELAYCLIENT

+environment variable is not set.

+For more information, please have a look at doc/README.qregex.

 .TP 5

 .I databytes

 Maximum number of bytes allowed in a message,

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/qmail-smtpd.c ./netqmail-1.05/netqmail-1.05/qmail-smtpd.c

--- ./netqmail-1.05.orig/netqmail-1.05/qmail-smtpd.c	2004-06-04 21:51:58.000000000 -0400

+++ ./netqmail-1.05/netqmail-1.05/qmail-smtpd.c	2006-04-23 00:12:33.441582382 -0400

@@ -23,6 +23,15 @@

 #include "timeoutread.h"

 #include "timeoutwrite.h"

 #include "commands.h"

+#include "qregex.h"

+#include "strerr.h"

+

+#define BMCHECK_BMF 0

+#define BMCHECK_BMFNR 1

+#define BMCHECK_BMT 2

+#define BMCHECK_BMTNR 3

+#define BMCHECK_BHELO 4

+    

 #define MAXHOPS 100

 unsigned int databytes = 0;

@@ -49,7 +58,9 @@

 void die_ipme() { out("421 unable to figure out my IP addresses (#4.3.0)\r\n"); flush(); _exit(1); }

 void straynewline() { out("451 See http://pobox.com/~djb/docs/smtplf.html.\r\n"); flush(); _exit(1); }

-void err_bmf() { out("553 sorry, your envelope sender is in my badmailfrom list (#5.7.1)\r\n"); }

+void err_bmf() { out("553 sorry, your envelope sender has been denied (#5.7.1)\r\n"); }

+void err_bmt() { out("553 sorry, your envelope recipient has been denied (#5.7.1)\r\n"); }

+void err_bhelo() { out("553 sorry, your HELO host name has been denied (#5.7.1)\r\n"); }

 void err_nogateway() { out("553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)\r\n"); }

 void err_unimpl(arg) char *arg; { out("502 unimplemented (#5.5.1)\r\n"); }

 void err_syntax() { out("555 syntax error (#5.5.4)\r\n"); }

@@ -93,9 +104,24 @@

 int liphostok = 0;

 stralloc liphost = {0};

+

 int bmfok = 0;

 stralloc bmf = {0};

-struct constmap mapbmf;

+

+int bmfnrok = 0;

+stralloc bmfnr = {0};

+

+int bmtok = 0;

+stralloc bmt = {0};

+

+int bmtnrok = 0;

+stralloc bmtnr = {0};

+

+int bhelook = 0;

+stralloc bhelo = {0};

+

+int logregex = 0;

+stralloc matchedregex = {0};

 void setup()

 {

@@ -114,8 +140,21 @@

   bmfok = control_readfile(&bmf,"control/badmailfrom",0);

   if (bmfok == -1) die_control();

-  if (bmfok)

-    if (!constmap_init(&mapbmf,bmf.s,bmf.len,0)) die_nomem();

+

+  bmfnrok = control_readfile(&bmfnr,"control/badmailfromnorelay",0);

+  if (bmfnrok == -1) die_control();

+

+  bmtok = control_readfile(&bmt,"control/badmailto",0);

+  if (bmtok == -1) die_control();

+

+  bmtnrok = control_readfile(&bmtnr,"control/badmailtonorelay",0);

+  if (bmtnrok == -1) die_control();

+

+  bhelook = control_readfile(&bhelo, "control/badhelo",0);

+  if (bhelook == -1) die_control();

+  if (env_get("NOBADHELO")) bhelook = 0;

+

+  if (env_get("LOGREGEX")) logregex = 1;

   if (control_readint(&databytes,"control/databytes") == -1) die_control();

   x = env_get("DATABYTES");

@@ -197,14 +236,56 @@

   return 1;

 }

-int bmfcheck()

+int bmcheck(which) int which;

 {

-  int j;

-  if (!bmfok) return 0;

-  if (constmap(&mapbmf,addr.s,addr.len - 1)) return 1;

-  j = byte_rchr(addr.s,addr.len,'@');

-  if (j < addr.len)

-    if (constmap(&mapbmf,addr.s + j,addr.len - j - 1)) return 1;

+  int i = 0;

+  int j = 0;

+  int x = 0;

+  int negate = 0;

+  static stralloc bmb = {0};

+  static stralloc curregex = {0};

+

+  if (which == BMCHECK_BMF) {

+    if (!stralloc_copy(&bmb,&bmf)) die_nomem();

+  } else if (which == BMCHECK_BMFNR) {

+    if (!stralloc_copy(&bmb,&bmfnr)) die_nomem();

+  } else if (which == BMCHECK_BMT) {

+    if (!stralloc_copy(&bmb,&bmt)) die_nomem();

+  } else if (which == BMCHECK_BMTNR) {

+    if (!stralloc_copy(&bmb,&bmtnr)) die_nomem();

+  } else if (which == BMCHECK_BHELO) {

+    if (!stralloc_copy(&bmb,&bhelo)) die_nomem();

+  } else {

+    die_control();

+  }

+

+  while (j < bmb.len) {

+    i = j;

+    while ((bmb.s[i] != '\0') && (i < bmb.len)) i++;

+    if (bmb.s[j] == '!') {

+      negate = 1;

+      j++;

+    }

+    if (!stralloc_copyb(&curregex,bmb.s + j,(i - j))) die_nomem();

+    if (!stralloc_0(&curregex)) die_nomem();

+    if (which == BMCHECK_BHELO) {

+      x = matchregex(helohost.s, curregex.s);

+    } else {

+      x = matchregex(addr.s, curregex.s);

+    }

+    if ((negate) && (x == 0)) {

+      if (!stralloc_copyb(&matchedregex,bmb.s + j - 1,(i - j + 1))) die_nomem();

+      if (!stralloc_0(&matchedregex)) die_nomem();      

+      return 1;

+    }

+    if (!(negate) && (x > 0)) {

+      if (!stralloc_copyb(&matchedregex,bmb.s + j,(i - j))) die_nomem();

+      if (!stralloc_0(&matchedregex)) die_nomem();

+      return 1;

+    }

+    j = i + 1;

+    negate = 0;

+  }

   return 0;

 }

@@ -218,7 +299,9 @@

 int seenmail = 0;

-int flagbarf; /* defined if seenmail */

+int flagbarfbmf; /* defined if seenmail */

+int flagbarfbmt;

+int flagbarfbhelo;

 stralloc mailfrom = {0};

 stralloc rcptto = {0};

@@ -226,11 +309,13 @@

 {

   smtp_greet("250 "); out("\r\n");

   seenmail = 0; dohelo(arg);

+  if (bhelook) flagbarfbhelo = bmcheck(BMCHECK_BHELO);

 }

 void smtp_ehlo(arg) char *arg;

 {

   smtp_greet("250-"); out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");

   seenmail = 0; dohelo(arg);

+  if (bhelook) flagbarfbhelo = bmcheck(BMCHECK_BHELO);

 }

 void smtp_rset(arg) char *arg;

 {

@@ -240,7 +325,11 @@

 void smtp_mail(arg) char *arg;

 {

   if (!addrparse(arg)) { err_syntax(); return; }

-  flagbarf = bmfcheck();

+  flagbarfbmf = 0; /* bmcheck is skipped for empty envelope senders */

+  if ((bmfok) && (addr.len != 1)) flagbarfbmf = bmcheck(BMCHECK_BMF);

+  if ((!flagbarfbmf) && (bmfnrok) && (addr.len != 1) && (!relayclient)) {

+    flagbarfbmf = bmcheck(BMCHECK_BMFNR);

+  }

   seenmail = 1;

   if (!stralloc_copys(&rcptto,"")) die_nomem();

   if (!stralloc_copys(&mailfrom,addr.s)) die_nomem();

@@ -250,7 +339,37 @@

 void smtp_rcpt(arg) char *arg; {

   if (!seenmail) { err_wantmail(); return; }

   if (!addrparse(arg)) { err_syntax(); return; }

-  if (flagbarf) { err_bmf(); return; }

+  if (flagbarfbhelo) {

+    if (logregex) {

+      strerr_warn6("qmail-smtpd: badhelo: <",helohost.s,"> at ",remoteip," matches pattern: ",matchedregex.s,0);

+    } else {

+      strerr_warn4("qmail-smtpd: badhelo: <",helohost.s,"> at ",remoteip,0);

+    }

+    err_bhelo();

+    return;

+  }

+  if (flagbarfbmf) {

+    if (logregex) {

+      strerr_warn6("qmail-smtpd: badmailfrom: <",mailfrom.s,"> at ",remoteip," matches pattern: ",matchedregex.s,0);

+    } else {

+      strerr_warn4("qmail-smtpd: badmailfrom: <",mailfrom.s,"> at ",remoteip,0);

+    }

+    err_bmf();

+    return;

+  }

+  if (bmtok) flagbarfbmt = bmcheck(BMCHECK_BMT);

+  if ((!flagbarfbmt) && (bmtnrok) && (!relayclient)) {

+    flagbarfbmt = bmcheck(BMCHECK_BMTNR);

+  }

+  if (flagbarfbmt) {

+    if (logregex) {

+      strerr_warn6("qmail-smtpd: badmailto: <",addr.s,"> at ",remoteip," matches pattern: ",matchedregex.s,0);

+    } else {

+      strerr_warn4("qmail-smtpd: badmailto: <",addr.s,"> at ",remoteip,0);

+    }

+    err_bmt();

+    return;

+  }

   if (relayclient) {

     --addr.len;

     if (!stralloc_cats(&addr,relayclient)) die_nomem();

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/qregex.c ./netqmail-1.05/netqmail-1.05/qregex.c

--- ./netqmail-1.05.orig/netqmail-1.05/qregex.c	1969-12-31 19:00:00.000000000 -0500

+++ ./netqmail-1.05/netqmail-1.05/qregex.c	2006-04-22 21:45:16.112776934 -0400

@@ -0,0 +1,57 @@

+/*

+ * qregex (v2)

+ * $Id: qregex.c,v 2.1 2001/12/28 07:05:21 evan Exp $

+ *

+ * Author  : Evan Borgstrom (evan at unixpimps dot org)

+ * Created : 2001/12/14 23:08:16

+ * Modified: $Date: 2001/12/28 07:05:21 $

+ * Revision: $Revision: 2.1 $

+ *

+ * Do POSIX regex matching on addresses for anti-relay / spam control.

+ * It logs to the maillog

+ * See the qregex-readme file included with this tarball.

+ * If you didn't get this file in a tarball please see the following URL:

+ *  http://www.unixpimps.org/software/qregex

+ *

+ * qregex.c is released under a BSD style copyright.

+ * See http://www.unixpimps.org/software/qregex/copyright.html

+ *

+ * Note: this revision follows the coding guidelines set forth by the rest of

+ *       the qmail code and that described at the following URL.

+ *       http://cr.yp.to/qmail/guarantee.html

+ * 

+ */

+

+#include <sys/types.h>

+#include <regex.h>

+#include "qregex.h"

+

+#define REGCOMP(X,Y)    regcomp(&X, Y, REG_EXTENDED|REG_ICASE)

+#define REGEXEC(X,Y)    regexec(&X, Y, (size_t)0, (regmatch_t *)0, (int)0)

+

+int matchregex(char *text, char *regex) {

+  regex_t qreg;

+  int retval = 0;

+

+

+  /* build the regex */

+  if ((retval = REGCOMP(qreg, regex)) != 0) {

+    regfree(&qreg);

+    return(-retval);

+  }

+

+  /* execute the regex */

+  if ((retval = REGEXEC(qreg, text)) != 0) {

+    /* did we just not match anything? */

+    if (retval == REG_NOMATCH) {

+      regfree(&qreg);

+      return(0);

+    }

+    regfree(&qreg);

+    return(-retval);

+  }

+

+  /* signal the match */

+  regfree(&qreg);

+  return(1);

+}

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/qregex.h ./netqmail-1.05/netqmail-1.05/qregex.h

--- ./netqmail-1.05.orig/netqmail-1.05/qregex.h	1969-12-31 19:00:00.000000000 -0500

+++ ./netqmail-1.05/netqmail-1.05/qregex.h	2006-04-22 21:45:16.112776934 -0400

@@ -0,0 +1,5 @@

+/* simple header file for the matchregex prototype */

+#ifndef _QREGEX_H_

+#define _QREGEX_H_

+int matchregex(char *text, char *regex);

+#endif

diff -u --unidirectional-new-file ./netqmail-1.05.orig/netqmail-1.05/README.qregex ./netqmail-1.05/netqmail-1.05/README.qregex

--- ./netqmail-1.05.orig/netqmail-1.05/README.qregex	1969-12-31 19:00:00.000000000 -0500

+++ ./netqmail-1.05/netqmail-1.05/README.qregex	2006-04-23 00:30:32.466336212 -0400

@@ -0,0 +1,203 @@

+QREGEX (v2) 20060423 - README April 23, 2006

+A Regular Expression matching patch for qmail 1.03 and netqmail

+

+

+OVERVIEW:

+

+qregex adds the ability to match address evelopes via Regular Expressions (REs)

+in the qmail-smtpd process. It has the abiltiy to match `helo/ehlo` (host name),

+`mail from` (envelope sender), and `rcpt to` (envelope recipient) commands.

+It follows all the base rules that are set out with qmail (ie using control

+files) so it makes for easy integretion into an existing setup (see the

+install instructions for more info). The v2 is specified because qregex was

+re-written to better conform to the security guarantee set forth by the author

+of qmail. The original version used stdio.h and stdlib.h for reading the

+control files whereas v2 now uses all stralloc functions which are much more

+regulated against buffer overruns and the like.

+See: http://cr.yp.to/qmail/guarantee.html

+

+

+FEATURES:

+

+Features of qregex include:

+

+1. Performs pattern matching on envelope senders and envelope

+   recipients against REs in the badmailfrom and badmailto control

+   files. Two additional control files, badmailfromnorelay and

+   badmailtonorelay, are used for pattern matching when the