Viktor Dukhovni:
> > -o soft_bounce=yes
> > -o smtp_fallback_relay=relayusa.example.com
>
> That said, neither form will forward rejected mail to the fallback
> relay. The soft-bounce feature operates at the wrong layer for that
> to happen. First the SMTP delivery agent gives up on the rejected
That seems to violate the principle of least astonishment. Conceptually,
soft-bounce means treat 5xx replies as 4xx replies.
The observed behavior originates from the time that Postfix, like
qmail, did not connect to an alternate SMTP server after receiving
a 4xx response.
This was fixed for the general case, but somehow the soft-bounce
feature was overlooked. I also note that the Postfix SMTP client
is the only program that tries to make alternate deliveries, so
this problem did not surface elsewhere in Postfix.
[I also recall that this came up a few years ago, but then there
was no time to address this properly].
Wietse
*** ./src/smtp/smtp_trouble.c- Sat Jan 14 20:09:23 2012
--- ./src/smtp/smtp_trouble.c Mon Jun 11 11:25:02 2012
***************
*** 151,156 ****
--- 151,157 ----
#include <mail_error.h>
#include <dsn_buf.h>
#include <dsn.h>
+ #include <mail_params.h>
/* Application-specific. */
***************
*** 190,195 ****
--- 191,197 ----
RECIPIENT *rcpt;
int status;
int soft_error = (STR(why->status)[0] == '4');
+ int soft_bounce_error = (STR(why->status)[0] == '5' &&
var_soft_bounce);
int nrcpt;
/*
***************
*** 197,203 ****
* delivery to a backup server. Just log something informative to show
* why we're skipping this host.
*/
! if (soft_error && (state->misc_flags & SMTP_MISC_FLAG_FINAL_SERVER) == 0)
{
msg_info("%s: %s", request->queue_id, STR(why->reason));
for (nrcpt = 0; nrcpt < SMTP_RCPT_LEFT(state); nrcpt++) {
rcpt = request->rcpt_list.info + nrcpt;
--- 199,206 ----
* delivery to a backup server. Just log something informative to show
* why we're skipping this host.
*/
! if ((soft_error || soft_bounce_error)
! && (state->misc_flags & SMTP_MISC_FLAG_FINAL_SERVER) == 0) {
msg_info("%s: %s", request->queue_id, STR(why->reason));
for (nrcpt = 0; nrcpt < SMTP_RCPT_LEFT(state); nrcpt++) {
rcpt = request->rcpt_list.info + nrcpt;
***************
*** 245,251 ****
state->status |= status;
}
if ((state->misc_flags & SMTP_MISC_FLAG_COMPLETE_SESSION) == 0
! && throttle_queue && soft_error && request->hop_status == 0)
request->hop_status = DSN_COPY(&why->dsn);
}
--- 248,255 ----
state->status |= status;
}
if ((state->misc_flags & SMTP_MISC_FLAG_COMPLETE_SESSION) == 0
! && throttle_queue && (soft_error || soft_bounce_error)
! && request->hop_status == 0)
request->hop_status = DSN_COPY(&why->dsn);
}
***************
*** 354,359 ****
--- 358,364 ----
DSN_BUF *why = state->why;
int status;
int soft_error;
+ int soft_bounce_error;
va_list ap;
/*
***************
*** 369,374 ****
--- 374,380 ----
vsmtp_fill_dsn(state, mta_name, resp->dsn, resp->str, format, ap);
va_end(ap);
soft_error = STR(why->status)[0] == '4';
+ soft_bounce_error = (STR(why->status)[0] == '5' && var_soft_bounce);
if (state->session && mta_name)
smtp_check_code(state->session, resp->code);
***************
*** 378,384 ****
* for trying other mail servers. Just log something informative to show
* why we're skipping this recipient now.
*/
! if (soft_error && (state->misc_flags & SMTP_MISC_FLAG_FINAL_SERVER) == 0)
{
msg_info("%s: %s", request->queue_id, STR(why->reason));
SMTP_RCPT_KEEP(state, rcpt);
}
--- 384,391 ----
* for trying other mail servers. Just log something informative to show
* why we're skipping this recipient now.
*/
! if ((soft_error || soft_bounce_error)
! && (state->misc_flags & SMTP_MISC_FLAG_FINAL_SERVER) == 0) {
msg_info("%s: %s", request->queue_id, STR(why->reason));
SMTP_RCPT_KEEP(state, rcpt);
}
*** ./src/smtp/Makefile.in- Sun Jan 22 10:55:20 2012
--- ./src/smtp/Makefile.in Mon Jun 11 11:23:52 2012
***************
*** 591,596 ****
--- 591,597 ----
smtp_trouble.o: ../../include/header_opts.h
smtp_trouble.o: ../../include/htable.h
smtp_trouble.o: ../../include/mail_error.h
+ smtp_trouble.o: ../../include/mail_params.h
smtp_trouble.o: ../../include/maps.h
smtp_trouble.o: ../../include/match_list.h
smtp_trouble.o: ../../include/mime_state.h
