-$Cambridge: exim/doc/doc-misc/WishList,v 1.62 2006/03/02 12:25:48 ph10 Exp $
-
EXIM 4 WISH LIST
----------------
+This Wish List is now obsolete. The items it contains have been imported into
+the Exim Bugzilla, which is where all new wishes should be added. This file is
+no longer maintained. Some day it should be deleted.
+
+
+===============================================================================
Even when it was first released, Exim 4 had a Wish List because not all the
things suggested for it were implemented. The list has not stopped growing...
mark david mcCreary
"I use the syntax_errors_to feature to email a copy of the error message.
-It would be helpful to have the X-Failed-Receipients header in there,
-identifying which addreses(s) are the problem, so that I don't have to
+It would be helpful to have the X-Failed-Recipients header in there,
+identifying which address(es) are the problem, so that I don't have to
parse the body of the email message to figure out which addresses."
------------------------------------------------------------------------------
So several warnings could be generated as the mailbox got bigger and bigger.
------------------------------------------------------------------------------
-(146) 15-May-2000 M Allow SMTP error codes in retry rules
-
-This would allow special handling of certain errors from certain hosts. In
-particular, it would allow failing of certain 4xx codes.
-
-This is now available for 4xx responses to RCPT commands. Is anything more
-needed? Apparently, yes; there's been a request for a similar feature for MAIL
-commands.
-------------------------------------------------------------------------------
-
(148) 15-May-2000 S Warn recipient if message rejected for quota excession.
Heinz Ekker
Is this really worth it? A per-transport value is also suggested - that would
mean remembering the value with each failed address and taking a minimum or
-a maximimum (which?).
+a maximum (which?).
------------------------------------------------------------------------------
(24) 21-Feb-02 ? A way of testing TLS using -bh
data transmitted for a non-delivery attempt.
------------------------------------------------------------------------------
-(69) 03-Jul-02 T Log selector to log whoson checs
+(69) 03-Jul-02 T Log selector to log whoson checks
Matt Bernstein
"I'd quite like a log_selector option which could spot you'd done a whoson
Peter A. Savitch
OpenLDAP 2.1 is going to be more popular (2.1.9 is available with many
-bug fixes). TLS-enabled LDAP is an interesting and usefull thing.
+bug fixes). TLS-enabled LDAP is an interesting and useful thing.
I can try to implement some things and send the patches, like with
ldapi.
that it can be used as a safety-net while testing configurations. Instead of a
local bounce, the message stays on the queue; instead of 5xx SMTP responses,
4xx ones are given.
-
-The ability to do the opposite - turn 4xx into 5xx under certain circumstances
-might also be useful (e.g. after a certain time). This might best be done by
-extending the retry logic to recognize 4xx as a special error. (This is now
-done.)
------------------------------------------------------------------------------
(202) 10-Oct-03 S -bvsomething to do a callout after the verify
------------------------------------------------------------------------------
(209) 31-Oct-03 S a way of making crashes in pipe commands temporary errors
-
------------------------------------------------------------------------------
(210) 31-Oct-03 S runtime option to change the daemon name used for tcprwappers
See also 333.
------------------------------------------------------------------------------
-(214) 05-Nov-03 S Put the wild part of local part prefix/suffx in variables
+(214) 05-Nov-03 S Put the wild part of local part prefix/suffix in variables
Unfortunately, this isn't quite as trivial as it seems.
------------------------------------------------------------------------------
changed.)
------------------------------------------------------------------------------
-(216) 27-Nov-03 S Option to bounce if required TLS doesn't happen
-
-This is for the smtp transport with hosts_require_tls set. Currently, it
-defers. Possibly the best approach is to make the error one that can be seen by
-the retry logic.
-------------------------------------------------------------------------------
-
(217) 27-Nov-03 M A function to pass back variables from Perl
This is a function that can be called from Perl, to take a name and a value and
(236) 02-Feb-04 S String in local_scan that's added to the binary version string
------------------------------------------------------------------------------
-(237) 02-Feb-04 M Add_header in ACLs because "message" is overloaded
-
-This would be useful for verbs where "message" is an error message. See also
-333.
-------------------------------------------------------------------------------
-
(238) 05-Feb-04 S ${address to handle multiple addresses
At present, ${address expects to see just one address. An extension would let
both of them.
------------------------------------------------------------------------------
-(286) 21-Jul-04 M Distinguishing a larger number of errors
-
-For instance, detecting "connection reset by peer" (ENETRESET or ECONNRESET)
-might be useful.
-------------------------------------------------------------------------------
-
(288) 10-Aug-04 M Option for verify to require MX
e.g. verify=sender/require_mx
(292) 13-Aug-04 M Overall timeout for message reception
-A client could in priciple keep an SMTP connection open for a very long time by
+A client could in principle keep an SMTP connection open for a very long time by
trickling in data very slowly. Also, after message_size_limit is exceeded, Exim
continues to swallow the data (though it does not write it to disk) until the
end is reached. Again, the connection could be held open for a very long time.
These are the main previous items:
Exim 3 Wish List: 41, 85, 149, 187.
-Exim 4 Wish List: 55, 62, 63, 160, 212, 237, 270, 314, 328.
+Exim 4 Wish List: 55, 62, 63, 160, 212, 270, 314, 328.
------------------------------------------------------------------------------
(334) 07-Jun-05 M Support for messages larger than 2G
The natural syntax for this would be to use a regex, like this:
${lookup regex{/some/file regex}{found-string}{not-found-string}}
+However, it would be natural to want to use $1 etc in the found-string; this
+would be hard because of the lookup caching (if repeated, the lookup won't
+actually be done and therefore the numerical variables won't be set), and in
+any case, even without caching (and it could, I suppose, be disabled for this
+lookup) those variables are not in the right storage pool even if they were
+preserved after the lookup.
+
+An alternative approach might be to implement something like this:
+
+ ${scanfile{/some/file}{sub-expression}}
+
+where the sub-expression is expanded for every line in the file, with each line
+in turn being put into $value. This is like a conditional ${readfile, and in
+fact ${readfile could be written using ${scanfile. It would be nice to find a
+way of stopping the scan once something has happened. The only thing I can
+think of is to invent a variable that changes when scanning a line generates
+some non-null text, and then always to stop on a forced failure. That would
+allow expressions like this:
+
+ ${scanfile{/some/file}
+ {
+ ${if eq{$generated}{}{${if match{regex}{$value}{something}}} fail}
+ }}
+
+It's all rather clumsy. Once a line has matched and generated some text, the
+next iteration would stop the scan. Another thought: maybe use $scanline
+instead of $value (to save confusion) and have $scantext containing everything
+that's been generated so far. That sounds pretty flexible.
------------------------------------------------------------------------------
(344) 10-Oct-05 M Make debug_print work in authenticators
enwildlsearch.
------------------------------------------------------------------------------
-(350) 28-Feb-06 S Additional errors for retry rules
+(351) 31-Mar-06 ? Allow some/all/a few internal variables to be set
+
+The original idea was to allow "set authenticated = x" to pretend a connection
+is authenticated after other conditions are true. This can, of course, be
+packaged up using macros in other ways. Setting other variables could cause
+problems.
+------------------------------------------------------------------------------
+
+(352) 04-Apr-06 S Add +accept_defer for host lists (and maybe others)
+
+At present, a defer causes a delivery defer. For non-critical ACLs there are
+times when it may be better to accept. See also 226 and 289.
+------------------------------------------------------------------------------
+
+(354) 30-Jun-06 ? Extensions to SMTP error codes
+
+A number of ideas arose following a discussion on the mailing list. I record
+them here so that they don't get lost. The motivations were to support the 551
+bounce code and enhanced status codes. Suggestions are to add a new ACL
+feature, possibly one of:
+
+ errorcode = 511
+ control = errorcode=551
+ message = 551 xxxx
+
+where in the last case, it's recognized by being 3 digits. In all cases, the
+first digit must be "right" for the circumstance - ignore or fault if not?
+
+To handle ESC, perhaps a new variable called $smtp_errorcode, settable by an
+option in a router when it fails, would do the trick. It could be used in any
+of the above modifiers.
+------------------------------------------------------------------------------
+
+(355) 30-Jun-06 ? Facility to permit experiments with SMTP extensions
+
+This is what was suggested:
+
+- adding some expansion variables: $ehlo_extensions (which will
+ hold the remote server supported smtp extensions announced
+ in the ehlo) and $rcpt_arguments with any RCPT extra argument
+
+- a main configuration option for adding ehlo extensions to the
+ ehlo response, like:
+
+ extra_ehlo_extensions = XFOO : XBAR
+
+- a extra option for the smtp transport to add arguments to
+ the RCPT TO command, like:
+
+ rcpt_args = FOO=BAR (will make exim issue RCPT TO:<a@b.c> FOO=BAR
+ when delivering that message)
+
+- a new acl for unknown smtp commands
-(i) Unexpected connection close; (ii) mail_4xx.
+This should be very simple to implement and will allow to make
+some experiments and implement custom extensions, i.e. one to
+known if remote client will redirect on 551 or not. Also the acl
+for unknown smtp command could be used for other purposes, like
+to detect and react to some kiddies that send things like
+http://... on the smtp port.
------------------------------------------------------------------------------
---- HWM 350 ------------------------------------------------------------------
+--- HWM 355 ------------------------------------------------------------------
---------------------------- End of WishList ---------------------------------
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