A. Schulze:
>
> wietse:
>
> > If it is DATA, then address verification is possible but it requires
> > source code
> > changes to Postfix:
> >
> > - After successful RCPT TO, do not assume that the recipient exists,
> > but send DATA and disconnect after the DATA response is received.
> >
> > This will cause extra noise in the logfile, therefore it should be
> > configurable:
> >
> > - Configure what sites reject recipients after DATA. The list of
> > such domains is limited, so this is not a big burden.
>
> this would be indeed a useful extension...
Patch follows. Most if not all *should* also work with Postfix 2.11
and possibly earlier versions.
This introduces a new parameter smtp_address_verify_target (default:
rcpt) that can be set to "data" for qmail-like servers.
Since this setting causes the Postfix SMTP client to hang up after
a positive DATA response, the remote SMTP server may log something
like this:
Dec 27 10:53:14 server postfix/smtpd[51624]: lost connection
after DATA (0 bytes) from host.example.org[192.168.1.3]
Dec 27 10:53:14 server postfix/smtpd[51624]: disconnect from
host.example.org[192.168.1.3] ehlo=1 mail=1 rcpt=1 data=0/1
Most of the patch is documentation and user interface stuff.
Wietse
20141227
Feature: smtp_address_verify_target (default: rcpt) that
determines what protocol stage decides if a recipient is
valid. Specify "data" for servers that reject recipients
after the DATA command. mantools/postlink, proto/postconf.proto,
global/mail_params.h, smtp/lmtp_params.c, smtp/smtp.c,
smtp/smtp.h, smtp/smtp_params.c, smtp/smtp_proto.c.
diff -cr /var/tmp/postfix-2.12-20141226/man/man5/postconf.5
./man/man5/postconf.5
*** /var/tmp/postfix-2.12-20141226/man/man5/postconf.5 2014-12-21
19:49:22.000000000 -0500
--- ./man/man5/postconf.5 2014-12-27 10:47:44.000000000 -0500
***************
*** 2472,2477 ****
--- 2472,2484 ----
configuration parameter. See there for details.
.PP
This feature is available in Postfix 2.8 and later.
+ .SH lmtp_address_verify_target (default: rcpt)
+ The LMTP protocol stage that determines whether a recipient is
+ deliverable. Specify one of "rcpt" or "data". The latter is needed
+ with remote LMTP servers that reject recipients after the DATA
+ command.
+ .PP
+ This feature is available in Postfix 2.12 and later.
.SH lmtp_assume_final (default: no)
When a remote LMTP server announces no DSN support, assume that
the
***************
*** 6085,6090 ****
--- 6092,6104 ----
.br
.PP
This feature is available in Postfix 2.8 and later.
+ .SH smtp_address_verify_target (default: rcpt)
+ The SMTP protocol stage that determines whether a recipient is
+ deliverable. Specify one of "rcpt" or "data". The latter is needed
+ with remote SMTP servers that reject recipients after the DATA
+ command.
+ .PP
+ This feature is available in Postfix 2.12 and later.
.SH smtp_always_send_ehlo (default: yes)
Always send EHLO at the start of an SMTP session.
.PP
diff -cr /var/tmp/postfix-2.12-20141226/man/man8/smtp.8 ./man/man8/smtp.8
*** /var/tmp/postfix-2.12-20141226/man/man8/smtp.8 2014-12-25
11:52:01.000000000 -0500
--- ./man/man8/smtp.8 2014-12-27 10:47:44.000000000 -0500
***************
*** 725,730 ****
--- 725,735 ----
.IP "\fBsmtp_fallback_relay ($fallback_relay)\fR"
Optional list of relay hosts for SMTP destinations that can't be
found or that are unreachable.
+ .PP
+ Available with Postfix 2.12 and later:
+ .IP "\fBsmtp_address_verify_target (rcpt)\fR"
+ The SMTP protocol stage that determines whether a recipient is
+ deliverable.
.SH "SEE ALSO"
.na
.nf
diff -cr /var/tmp/postfix-2.12-20141226/mantools/postlink ./mantools/postlink
*** /var/tmp/postfix-2.12-20141226/mantools/postlink 2014-12-12
20:44:45.000000000 -0500
--- ./mantools/postlink 2014-12-27 10:38:24.000000000 -0500
***************
*** 89,94 ****
--- 89,96 ----
s;\baddress_verify_service_name\b;<a
href="postconf.5.html#address_verify_service_name">$&</a>;g;
s;\baddress_verify_transport_maps\b;<a
href="postconf.5.html#address_verify_transport_maps">$&</a>;g;
s;\baddress_verify_virtual_transport\b;<a
href="postconf.5.html#address_verify_virtual_transport">$&</a>;g;
+ s;\bsmtp_address_verify_target\b;<a
href="postconf.5.html#smtp_address_verify_target">$&</a>;g;
+ s;\blmtp_address_verify_target\b;<a
href="postconf.5.html#lmtp_address_verify_target">$&</a>;g;
s;\balias_database\b;<a href="postconf.5.html#alias_database">$&</a>;g;
s;\balias_maps\b;<a href="postconf.5.html#alias_maps">$&</a>;g;
s;\ballow_mail_to_com[-</bB>]*\n*[ <bB>]*mands\b;<a
href="postconf.5.html#allow_mail_to_commands">$&</a>;g;
diff -cr /var/tmp/postfix-2.12-20141226/proto/postconf.proto
./proto/postconf.proto
*** /var/tmp/postfix-2.12-20141226/proto/postconf.proto 2014-12-21
19:47:44.000000000 -0500
--- ./proto/postconf.proto 2014-12-27 10:37:56.000000000 -0500
***************
*** 15419,15424 ****
--- 15419,15442 ----
<p> This feature is available in Postfix 2.9 and later. </p>
+ %PARAM smtp_address_verify_target rcpt
+
+ <p> The SMTP protocol stage that determines whether a recipient is
+ deliverable. Specify one of "rcpt" or "data". The latter is needed
+ with remote SMTP servers that reject recipients after the DATA
+ command. </p>
+
+ <p> This feature is available in Postfix 2.12 and later. </p>
+
+ %PARAM lmtp_address_verify_target rcpt
+
+ <p> The LMTP protocol stage that determines whether a recipient is
+ deliverable. Specify one of "rcpt" or "data". The latter is needed
+ with remote LMTP servers that reject recipients after the DATA
+ command. </p>
+
+ <p> This feature is available in Postfix 2.12 and later. </p>
+
%PARAM daemon_table_open_error_is_fatal no
<p> How a Postfix daemon process handles errors while opening lookup
diff -cr /var/tmp/postfix-2.12-20141226/src/global/mail_params.h
./src/global/mail_params.h
*** /var/tmp/postfix-2.12-20141226/src/global/mail_params.h 2014-12-12
20:42:53.000000000 -0500
--- ./src/global/mail_params.h 2014-12-27 10:44:18.000000000 -0500
***************
*** 2778,2783 ****
--- 2778,2791 ----
#define DEF_VRFY_XPORT_MAPS "$" VAR_TRANSPORT_MAPS
extern char *var_vrfy_xport_maps;
+ #define SMTP_VRFY_TGT_RCPT "rcpt"
+ #define SMTP_VRFY_TGT_DATA "data"
+ #define VAR_LMTP_VRFY_TGT "lmtp_address_verify_target"
+ #define DEF_LMTP_VRFY_TGT SMTP_VRFY_TGT_RCPT
+ #define VAR_SMTP_VRFY_TGT "smtp_address_verify_target"
+ #define DEF_SMTP_VRFY_TGT SMTP_VRFY_TGT_RCPT
+ extern char *var_smtp_vrfy_tgt;
+
/*
* Message delivery trace service.
*/
diff -cr /var/tmp/postfix-2.12-20141226/src/smtp/lmtp_params.c
./src/smtp/lmtp_params.c
*** /var/tmp/postfix-2.12-20141226/src/smtp/lmtp_params.c 2014-11-27
12:18:44.000000000 -0500
--- ./src/smtp/lmtp_params.c 2014-12-27 10:43:46.000000000 -0500
***************
*** 33,38 ****
--- 33,39 ----
VAR_LMTP_SASL_TYPE, DEF_LMTP_SASL_TYPE, &var_smtp_sasl_type, 1, 0,
VAR_LMTP_BIND_ADDR, DEF_LMTP_BIND_ADDR, &var_smtp_bind_addr, 0, 0,
VAR_LMTP_BIND_ADDR6, DEF_LMTP_BIND_ADDR6, &var_smtp_bind_addr6, 0, 0,
+ VAR_LMTP_VRFY_TGT, DEF_LMTP_VRFY_TGT, &var_smtp_vrfy_tgt, 1, 0,
VAR_LMTP_HELO_NAME, DEF_LMTP_HELO_NAME, &var_smtp_helo_name, 1, 0,
VAR_LMTP_HOST_LOOKUP, DEF_LMTP_HOST_LOOKUP, &var_smtp_host_lookup, 1, 0,
VAR_LMTP_DNS_SUPPORT, DEF_LMTP_DNS_SUPPORT, &var_smtp_dns_support, 0, 0,
diff -cr /var/tmp/postfix-2.12-20141226/src/smtp/smtp.c ./src/smtp/smtp.c
*** /var/tmp/postfix-2.12-20141226/src/smtp/smtp.c 2014-12-25
11:47:18.000000000 -0500
--- ./src/smtp/smtp.c 2014-12-27 10:47:44.000000000 -0500
***************
*** 685,690 ****
--- 685,695 ----
/* .IP "\fBsmtp_fallback_relay ($fallback_relay)\fR"
/* Optional list of relay hosts for SMTP destinations that can't be
/* found or that are unreachable.
+ /* .PP
+ /* Available with Postfix 2.12 and later:
+ /* .IP "\fBsmtp_address_verify_target (rcpt)\fR"
+ /* The SMTP protocol stage that determines whether a recipient is
+ /* deliverable.
/* SEE ALSO
/* generic(5), output address rewriting
/* header_checks(5), message header content inspection
***************
*** 816,821 ****
--- 821,827 ----
char *var_smtp_sasl_type;
char *var_smtp_bind_addr;
char *var_smtp_bind_addr6;
+ char *var_smtp_vrfy_tgt;
bool var_smtp_rand_addr;
int var_smtp_pix_thresh;
int var_queue_run_delay;
***************
*** 1077,1082 ****
--- 1083,1093 ----
*/
smtp_dns_res_opt = name_mask(VAR_LMTP_SMTP(DNS_RES_OPT),
dns_res_opt_masks,
var_smtp_dns_res_opt);
+
+ /*
+ * Address verification.
+ */
+ smtp_vrfy_init();
}
/* pre_init - pre-jail initialization */
diff -cr /var/tmp/postfix-2.12-20141226/src/smtp/smtp.h ./src/smtp/smtp.h
*** /var/tmp/postfix-2.12-20141226/src/smtp/smtp.h 2014-12-02
17:37:41.000000000 -0500
--- ./src/smtp/smtp.h 2014-12-27 10:44:43.000000000 -0500
***************
*** 365,370 ****
--- 365,371 ----
/*
* smtp_proto.c
*/
+ extern void smtp_vrfy_init(void);
extern int smtp_helo(SMTP_STATE *);
extern int smtp_xfer(SMTP_STATE *);
extern int smtp_rset(SMTP_STATE *);
diff -cr /var/tmp/postfix-2.12-20141226/src/smtp/smtp_params.c
./src/smtp/smtp_params.c
*** /var/tmp/postfix-2.12-20141226/src/smtp/smtp_params.c 2014-11-27
12:18:44.000000000 -0500
--- ./src/smtp/smtp_params.c 2014-12-27 10:42:04.000000000 -0500
***************
*** 34,39 ****
--- 34,40 ----
VAR_SMTP_SASL_TYPE, DEF_SMTP_SASL_TYPE, &var_smtp_sasl_type, 1, 0,
VAR_SMTP_BIND_ADDR, DEF_SMTP_BIND_ADDR, &var_smtp_bind_addr, 0, 0,
VAR_SMTP_BIND_ADDR6, DEF_SMTP_BIND_ADDR6, &var_smtp_bind_addr6, 0, 0,
+ VAR_SMTP_VRFY_TGT, DEF_SMTP_VRFY_TGT, &var_smtp_vrfy_tgt, 1, 0,
VAR_SMTP_HELO_NAME, DEF_SMTP_HELO_NAME, &var_smtp_helo_name, 1, 0,
VAR_SMTP_HOST_LOOKUP, DEF_SMTP_HOST_LOOKUP, &var_smtp_host_lookup, 1, 0,
VAR_SMTP_DNS_SUPPORT, DEF_SMTP_DNS_SUPPORT, &var_smtp_dns_support, 0, 0,
diff -cr /var/tmp/postfix-2.12-20141226/src/smtp/smtp_proto.c
./src/smtp/smtp_proto.c
*** /var/tmp/postfix-2.12-20141226/src/smtp/smtp_proto.c 2014-12-06
20:35:33.000000000 -0500
--- ./src/smtp/smtp_proto.c 2014-12-27 10:44:33.000000000 -0500
***************
*** 261,266 ****
--- 261,284 ----
smtp_text_out,
};
+ static int smtp_vrfy_tgt;
+
+ /* smtp_vrfy_init - initialize */
+
+ void smtp_vrfy_init(void)
+ {
+ static const NAME_CODE vrfy_init_table[] = {
+ SMTP_VRFY_TGT_RCPT, SMTP_STATE_RCPT,
+ SMTP_VRFY_TGT_DATA, SMTP_STATE_DATA,
+ 0,
+ };
+
+ if ((smtp_vrfy_tgt = name_code(vrfy_init_table, NAME_CODE_FLAG_NONE,
+ var_smtp_vrfy_tgt)) == 0)
+ msg_fatal("bad protocol stage: \"%s = %s\"",
+ VAR_SMTP_VRFY_TGT, var_smtp_vrfy_tgt);
+ }
+
/* smtp_helo - perform initial handshake with SMTP server */
int smtp_helo(SMTP_STATE *state)
***************
*** 1541,1547 ****
dsn_notify_str(rcpt->dsn_notify));
}
if ((next_rcpt = send_rcpt + 1) == SMTP_RCPT_LEFT(state))
! next_state = DEL_REQ_TRACE_ONLY(request->flags) ?
SMTP_STATE_ABORT : SMTP_STATE_DATA;
break;
--- 1559,1566 ----
dsn_notify_str(rcpt->dsn_notify));
}
if ((next_rcpt = send_rcpt + 1) == SMTP_RCPT_LEFT(state))
! next_state = (DEL_REQ_TRACE_ONLY(request->flags)
! && smtp_vrfy_tgt == SMTP_STATE_RCPT) ?
SMTP_STATE_ABORT : SMTP_STATE_DATA;
break;
***************
*** 1551,1557 ****
*/
case SMTP_STATE_DATA:
vstring_strcpy(next_command, "DATA");
! next_state = SMTP_STATE_DOT;
break;
/*
--- 1570,1578 ----
*/
case SMTP_STATE_DATA:
vstring_strcpy(next_command, "DATA");
! next_state = (DEL_REQ_TRACE_ONLY(request->flags)
! && smtp_vrfy_tgt == SMTP_STATE_DATA) ?
! SMTP_STATE_LAST : SMTP_STATE_DOT;
break;
/*
