-$Cambridge: exim/doc/doc-misc/WishList,v 1.25 2005/03/15 15:36:41 ph10 Exp $
+$Cambridge: exim/doc/doc-misc/WishList,v 1.70 2007/02/27 11:51:27 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+no longer maintained.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...
The problem with header_remove followed by header_add is that you can't refer
to the previous value of the header when adding a replacement. This could be
-solved with a replace_header option.
+solved with a replace_header option. See also Exim 4/333.
------------------------------------------------------------------------------
(43) 15-Oct-98 M Sender rewrite *after* SMTP incoming checks
Dave Lewney
John Holman
-Such as "return-receipt-to". See also 41.
+Such as "return-receipt-to". See also 41. See also Exim 4/333.
------------------------------------------------------------------------------
(90) 21-Apr-99 M change wild prefix/suffix greediness
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?
-------------------------------------------------------------------------------
-
(148) 15-May-2000 S Warn recipient if message rejected for quota excession.
Heinz Ekker
A separate but related issue is the effect of headers added by "unseen"
directors. These are documented in chapter 19 as not being accumulated. Should
-any change be made?
+any change be made? See also Exim 4/333.
------------------------------------------------------------------------------
(155) 16-Jun-2000 M Special handling for certain hosts
address?
------------------------------------------------------------------------------
-(172) 11-Sep-2000 S Allow file/directory in appendfile to override
-"Michael J. Tubby"
-
-When appendfile is called from forward or filter files, it ignores file or
-directory settings. Maybe they should override. The path set by the forward or
-filter is available in $address_file these days, so it could be used to create
-a longer path.
-------------------------------------------------------------------------------
-
(173) 18-Sep-2000 S A way of doing lsearches with EOL terminated keys
Jason Robertson
exim_dbmbuild to make them into DBM files.
------------------------------------------------------------------------------
-(174) 19-Sep-2000 S A way of using a different port for fallback hosts.
-Dean Brooks
-------------------------------------------------------------------------------
-
(181) 10-Nov-2000 S Compile-time options for ignoring Sendmail options
So that new ones could be accommodated easily.
headers_remove = "X-*:Additional-header"
------------------------------------------------------------------------------
-(188) 02-Jan-2001 S Make pipe timeout a temporary error
-Georg v.Zezschwitz
-
-A way to make a timeout into a temporary error.
-------------------------------------------------------------------------------
-
(190) 03-Jan-2001 M Multiple message operations in eximon
------------------------------------------------------------------------------
might have. At ACL time, one would need to verify the recipient, and determine
that it routed to host X.
-. A new lookup library that operates on a specially prepared file of IP
-addresses and masks so that a single "lookup" yields a yes/no answer. This
-should be a freestanding thing - needs a utility to build the file from a list.
-
. People want to change the wording of messages; can we find an efficient way
of allowing this? (Maybe put all messages into a separate module?) The problem
is not in the messages themselves, but in the values that get inserted into
. Implement randomize for ldap/sql servers.
. Add an option for ETRN that says "wait for the command to finish, and use its
-stdout as the SMTP response."
+stdout as the SMTP response." // A serialized ETRN now does the waiting, but
+there is as yet no way to use the status. //
. -odsomething for "ignore retry when doing immediate delivery".
it were 4xx. Or possible add a sophisticated "after command X, treat xxx as
yyy".
-. A way of rewriting addresses in non-standard header lines such as
-Mail-Followup-To.
-
. Global option to enable initgroups() for exim uid. Default off.
. When verifying a sender, should it be rewritten with any T rewrites, because
. Options and/or a utility to enable non-privileged users to view the queue
(e.g. -bpp), manipulate their own messages, etc.
-. Specify a port along with a host in a route_list.
-
. A generalized "From" escaping scheme that also escapes >From so that the
whole thing can be reversed.
John W Baxter
May be tricky, because at the higher levels, the format of the query is not
-understood.
-------------------------------------------------------------------------------
-
-(8) 01-Jan-02 S Expand once_repeat in autoreply
-John Jetmore
+understood. // There is now a fudge that works in some cases. See ChangeLog
+4.51/PH/10. //
------------------------------------------------------------------------------
(9) 01-Jan-02 S Headers as well as body in file for autoreply
feature would use a regex to match whole lines and replace them. It could be
useful for patching up syntactically invalid lines from crappy clients, before
the syntax check kicks in. (It might also be useful for hiding local host names
-in Received: headers.)
+in Received: headers.) See also 333.
------------------------------------------------------------------------------
(58) 26-Jun-02 ? Extend PAM support
"I'd like to be able to give Exim a list of headers that must be removed
from the message at arrival, before data_acl processing (and before the
-rcpt_acl warn headers are added to the message)."
+rcpt_acl warn headers are added to the message)." See also 333.
------------------------------------------------------------------------------
(63) 28-Jun-02 S Access to ACL-added headers in ACLs
"I'd like also to be able to look at the already added headers by a
rcpt_acl when still checking rcpt_acl (either later in the acl for the same
-RCPT TO or for another RCPT TO)."
+RCPT TO or for another RCPT TO)." See also 333.
------------------------------------------------------------------------------
(65) 28-Jun-02 M Expand fallback hosts
copies to the same address.
------------------------------------------------------------------------------
-(73) 17-Jul-02 M Match a list from within a condition
-
-e.g. ${if matchdomain {$domain}{+domainlist} ...
- ${if matchhost {$sender_host_address}{1.2.3.4/10:2.3.4.5/16}...
-
-Thought needed about how to handle host names. This may be too messy to specify
-cleanly.
-
-22-Apr-04: Implemented for domains, addresses, and local parts. Hosts are
-too messy!
-
-The only sensible approach seems to be to allow IP address arguments only.
-Anything else should be diagnosed as an error. However, if a name appears in
-the list, a PTR lookup should be done. This may require a lot of refactoring
-in the code, because of the current assumption that were are (almost) always
-dealing with THE sending host.
-------------------------------------------------------------------------------
-
(74) 22-Jul-02 M Extend -bV to do more semantic checking
For example, diagnose "local_hosts" that should probably be "+local_hosts".
------------------------------------------------------------------------------
(160) 19-May-03 M Remove headers using wild cards
+
+See also 333.
------------------------------------------------------------------------------
(162) 28-May-03 M/L Use of real numbers in filters, expansions, and options
Suggested patch supplied.
------------------------------------------------------------------------------
-(171) 23-Jun-03 S Option to make timeout a soft failure on pipe transport
-
-------------------------------------------------------------------------------
-
(172) 23-Jun-03 M Option to make SQL query to specific server
------------------------------------------------------------------------------
different kinds of verify failure.
------------------------------------------------------------------------------
-(196) 30-Sep-03 S A way of detecting whether it was HELO or EHLO in the ACL
-
-$received_protocol isn't reset until after the command is accepted (which
-seems right), and $smtp_data shows only the arguments. Maybe $smtp_command?
-------------------------------------------------------------------------------
-
(197) 30-Sep-03 S MACROS_DROP_PRIVS and ALT_CONFIG_DROP_PRIVS
Now that alternative configurations can be restricted to certain directories,
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
------------------------------------------------------------------------------
(212) 31-Oct-03 M specify headers lines in HELO ACL to be added to all msgs
+
+See also 333.
------------------------------------------------------------------------------
(214) 05-Nov-03 S Put the wild part of local part prefix/suffx in variables
Unfortunately, this isn't quite as trivial as it seems.
------------------------------------------------------------------------------
-(215) 14-Nov-03 S A way of turning off message-submission fix-ups
-
-Globally, and perhaps also via an ACL control so that it can be done on a
-per-message basis. Is this still needed? Since this item was added to this
-list, default fixups for non-local messages have been removed, and control =
-submission has been added.
-------------------------------------------------------------------------------
-
(215) 26-Nov-03 M/L Conversion of IDNA domain names for logging
IDNA (RFCs 3490-3492) converts domains names containing non-ASCII characters
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.
-------------------------------------------------------------------------------
-
(238) 05-Feb-04 S ${address to handle multiple addresses
At present, ${address expects to see just one address. An extension would let
will be required.
This can now be done fairly generally from local_scan(), and at the start and
-after the Received: block from an ACL. Is anything more needed?
+after the Received: block from an ACL. Is anything more needed? See also 333.
------------------------------------------------------------------------------
(271) 02-Jun-04 L Callouts at routing time
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
AUTH during the callout checking, on all types of connection. I suppose that
means making TLS available as well. This probably means a rewrite of the code
that actually does the callout. Should we use the relevant transport in a new
-"callout" mode instead of keeping things separate? See also 253.
+"callout" mode instead of keeping things separate? See also 253 and 323.
And here's another submitted idea: "My actual suggestion is that if this model
is followed, the parent process doesn't have to stop the callout process if it
(314) 15-Feb-05 M Multiple headers_{add,remove} for routers
If headers_{add,remove} could be specified multiple times, it would be easier
-for those people that construct configs using .ifdef or .include, etc.
+for those people that construct configs using .ifdef or .include, etc. See also
+333.
------------------------------------------------------------------------------
(315) 15-Feb-05 M String variables for use in filters.
solutions with a similar requirement."
------------------------------------------------------------------------------
-(320) 03-Mar-05 T Options to control daemon retry binding
-
-Currently the daemon tries 10 times at 30-second intervals to listen on an IP
-address. The wish is for options to control these numbers.
-------------------------------------------------------------------------------
-
(321) 07-Mar-05 S Run an ACL on a sync error
... and possibly "accept" or "deny" it.
(322) 15-Mar-05 M Add a /defer_ok option to verify=reverse_host_lookup
------------------------------------------------------------------------------
---- HWM 322 ------------------------------------------------------------------
+
+(323) 15-Mar-05 M Make callouts use smtp_data from the smtp transport
+
+This is yet another problem caused by duplicating the SMTP code between the
+transport and the callout verification. See item 294 above. Merging the
+transport and the callout code could prevent this kind of thing from happening.
+------------------------------------------------------------------------------
+
+(324) 04-Apr-05 ? Make -bP show ACLs
+
+This is in the Bugzilla as #10.
+------------------------------------------------------------------------------
+
+(326) 03-May-05 ? Queue-only on memory shortage
+
+This is bugzilla #17. The idea is to have something like queue_only_load that
+triggers on a shortage of main memory.
+------------------------------------------------------------------------------
+
+(327) 06-May-05 ? Break delay if connection drops
+
+Currently, "delay=5m" (e.g.) waits for 5 minutes. If we can detect that the
+connection has died in the meantime, it would make sense to break the delay.
+However, it doesn't seem possible to detect a dropped connection without trying
+to read from it.
+------------------------------------------------------------------------------
+
+(328) 10-May-05 S After "unseen" routing, pass on header additions/deletions
+
+Currently, when an "unseen" router accepts an address, header additions and
+deletions stick with that address, and the "clone" address that continues to be
+routed starts off without any additions or removals. This request is for an
+option to select other actions: retain header actions with the clone only, or
+pass them on to both addresses. See also 333.
+------------------------------------------------------------------------------
+
+(329) 12-May-05 S Create message ID at MAIL FROM time
+
+Currently, the ID is created only when Exim is about to create the data (-D)
+file for an incoming message. In other words, after it knows it really is going
+to accept the message. Creating the ID earlier would mean that rejection
+messages in the log would be tagged with an ID, and this is seen as desirable
+by some people.
+------------------------------------------------------------------------------
+
+(330) 31-May-05 ? Default interface for -bh and default port for -oMi
+
+I do not think it worth putting effort in here for these reasons: If a host has
+multiple interfaces, there's no easy way to choose one to be the default for
+$interface_address when -bh is used. If the host does not have multiple
+interfaces, chances are the configuration won't be looking at
+$interface_address anyway. If you are setting -oMi, and care about the port, it
+isn't much effort to tack on a port number, though in this case, I suppose a
+default of 25 is "obvious".
+------------------------------------------------------------------------------
+
+(331) 31-May-05 M More than one retry time per host
+
+Consider this example: an attempt to start a TLS connection to a host gets a
+temporary error. This stops *all* connections, both for TLS and otherwise.
+Different retry times for different circumstances are needed to get round this.
+What are the circumstances? TLS/not-TLS is clearly one, but sometimes you don't
+know if you are going to try TLS until you have connected. So this makes sense
+only if require_tls is used. Perhaps the multiple retry times should just be
+per-transport, to avoid these difficulties. If we made all retry keys depend on
+the transport, this would happen automatically.
+------------------------------------------------------------------------------
+
+(332) 03-Jun-05 S A "receive time taken" log selector
+
+This suggestion is to at an RT= item to the <= line, giving the time it
+actually took to receive the message.
+------------------------------------------------------------------------------
+
+(333) 06-Jun-05 L Re-think and re-implement header handling
+
+There are a number of items related to headers above. Better facilities for
+handling headers at ACL time are needed. The whole way in which Exim handles
+headers should be re-planned and re-implemented in a more consistent manner.
+
+These are the main previous items:
+
+Exim 3 Wish List: 41, 85, 149, 187.
+Exim 4 Wish List: 55, 62, 63, 160, 212, 270, 314, 328.
+------------------------------------------------------------------------------
+
+(334) 07-Jun-05 M Support for messages larger than 2G
+
+This is probably a longish-term thing at the moment. Quotas over 2G are now
+supported, but not individual messages; no doubt one day this will be wanted.
+------------------------------------------------------------------------------
+
+(336) 16-Jun-05 M Show recipient(s) after header check failure
+
+The mainlog line for "There is no valid sender in any header line" shows the
+sending host and the envelope sender, but does not show any recipients. There
+has been a request to show recipients. Presumably this should be on some new
+log selector, and it must have a cutoff maximum number of recipients. NOTE: the
+data in the reject log does show the envelope recipients as part of its
+additional data.
+------------------------------------------------------------------------------
+
+(337) 29-Jun-05 S Add "defer" to $recipient_verify_failure
+
+This is for when defer_ok was set when verifying recipients. Since this isn't
+for a failure, we probably also need "ok" for the non-fail case.
+------------------------------------------------------------------------------
+
+(338) 14-Jul-05 M Change to Bind 9 API
+
+Exim uses the original API for calling the DNS resolver. There is a newer API
+available, and noises are being made in some OS that compatibility with the old
+API is going to be dropped. Nevertheless, there are sure to be systems about
+for ages that require the use of the old API. Therefore, we will have to
+implement not only an interface to the new API, but a backwards compatibility
+feature. It would be nice if this was automatic.
+------------------------------------------------------------------------------
+
+(339) 28-Jul-05 S Log name of maildir file
+
+This wish is for an option to log the name of the file that is written in
+maildir format (e.g. time.pid.host).
+------------------------------------------------------------------------------
+
+(340) 30-Aug-05 M Match more than one item
+
+match_address, for instance, matches one address to a list. The wish is to be
+able to supply two lists; for each address in the first list, search the
+second. Maybe something like ${match_any{...}{...}} is needed.
+------------------------------------------------------------------------------
+
+(341) 15-Sep-05 S Add /return_path_retain to submission mode
+
+This would re-instate the behaviour prior to change 4.52/PH/04.
+------------------------------------------------------------------------------
+
+(342) 26-Sep-05 T Log and maybe defer odd values for condition pre-condition
+
+Odd values for "condition" in an ACL cause it to defer. In a router, they are
+treated as "true". At least they should be logged in a router, and perhaps they
+should also defer, for compatibility with ACLs.
+------------------------------------------------------------------------------
+
+(343) 03-Oct-05 M A query-style lookup for scanning flat files
+
+The natural syntax for this would be to use a regex, like this:
+${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
+------------------------------------------------------------------------------
+
+(345) 14-Oct-05 M Standardize rejection messages
+
+"The parsing for rejection lines is a bit of a mess, and fairly
+unmaintainable. Do you think it would be possible to standardise
+rejection/refusal log messages? How about something like:
+
+(<ID>|16 Spaces) *< (Connection|MAIL|RCPT|HELO|EHLO|DATA) rejected (from
+<Address>)?: <Reason> (\(<Detail>\))?"
+------------------------------------------------------------------------------
+
+(346) 20-Oct-05 S Set $domain and $local_part in retry matching
+
+Currently, these variables are unset. Make it like rewrite matching.
+------------------------------------------------------------------------------
+
+(347) 15-Nov-05 M Arrange to expand data from wildlsearch
+
+This would allow keys that are regular expressions to set up numerical
+variables that are included in the data. This has to be done inside the lookup
+code, because of caching. Probably means we have to invent ewildlsearch and
+enwildlsearch.
+------------------------------------------------------------------------------
+
+(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
+
+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 smpt command could be used for other purposes, like
+to dectect and react to some kiddies that send things like
+http://... on the smtp port.
+------------------------------------------------------------------------------
+--- HWM 355 ------------------------------------------------------------------
---------------------------- End of WishList ---------------------------------
git://git.exim.org / exim.git / blobdiff