Re: [exim-dev] [Bug 2078] New: exim breaks if current directory doesn't exist

[Graeme Fowler via Exim-dev]

On 16 Mar 2017, at 16:57, ad...@bugs.exim.org  
wrote:
> Exim should not require the working directory to exist. Wasted 10 hours
> figuring out why cron-jobs script never sent anything.
> 
> $ tmpdir=`mktemp --directory /tmp/dispenser-test.XXX`
> $ cd $tmpdir
> $ rm -rf $tmpdir
> $ mail -s "Test email" "$USER" <<< 'MyData'
> exim: can't get the current working directory: No such file or directory

Change was in 4.87 as part of the environment cleanup work, keeping initial_cwd 
(and making it available in $initial_cwd).

This is an unusual corner case, IMO. I don't think I've ever come across 
something calling an application when it's explicitly not got a CWD in this way!

Graeme


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Re: [exim-dev] Exim: Universal Acceptance Evaluation for Readiness

[Graeme Fowler via Exim-dev]

Hi June

On 12 Dec 2018, at 02:29, June Lau via Exim-dev  wrote:
> I am June from the Universal Acceptance Steering Group, a community-based
> team around the world with a primary objective to raise awareness and help
> software developers and platforms understand how to update their systems to
> keep pace with an evolving domain name system (DNS).
> 
> We hope to review Exim on its capability to accept all domain names and all
> email addresses, therefore looking for a technical manager to direct any
> inquiries to.  I would be grateful if you can provide a contact person for
> our evaluation purpose.  Thank you.

There is no ‘technical manager’; Exim is an open source project with a small 
team of developers keeping it going. We use a couple of mailing lists for 
end-user support and development, of which this is one - your postings to both 
were held for moderation as you’re not a subscriber.

We’re collectively happy to discuss your questions either here on on the 
exim-users list, but as we’ve allowed this message through it’s probably best 
to start here. Note that it would be best if you subscribed to the list in 
order that you participate in any discussion in a timely manner.

Regards

Graeme
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Re: [exim-dev] Mailop list: exim and google fighting over DKIM

[Graeme Fowler via Exim-dev]

On 30 Apr 2019, at 00:03, Jeremy Harris via Exim-dev  wrote:
> Bzzt.
> 
> Stop right there.
> 
> The ML adds body content.  This will invalidate the signature.
> 
> The header thing, even if you do game it, will not help that.

*shrug*

I was merely explaining the cogent points of the discussion on mailop, Jeremy, 
given comments by other list subscribers/bz posters on the private nature of 
the list.

Graeme
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Re: [exim-dev] Mailop list: exim and google fighting over DKIM

[Graeme Fowler via Exim-dev]

On 29 Apr 2019, at 19:26, Andrew C Aitchison via Exim-dev  
wrote:
> I will do so, either here or in that bug, when I can do so without causing 
> more heat.

The gist of the discussion (I’m a mailop subscriber) is manyfold:

1. Google accept messages over IPv6 but require stricter verification over IPv6 
than IPv4
2. mailop.org has no SPF record
3. mailop.org can deliver to Google over IPv6
4. Signed messages inbound to mailop.org (and other lists!) from Debian-derived 
and other setups using the default macro defined in pdkim.h can have headers 
added which have been declared signed when they’re not present*
5. Adding them invalidates the signature, and if the MLM software doesn’t 
remove or re-sign the message, that can be problematic if a receiving system is 
taking extra care with respect to verification
6. It appears Google will reject messages that combine elements 1 thru 5

* this is the bit I’m confused by; I have a large historical pile of messages 
to lists from me and I can’t see a signature with those headers included 
despite me using the defaults for a long period.

RFC4871 stated that a suggested list of headers SHOULD be signed, if existing.
RFC6376 dropped the SHOULD and provided an example of what constitutes the 
“core” of a message.

So *either* the Debian-derived configuration (of which the original poster 
mentioned they were using unaltered for DKIM purposes, inheriting defaults) 
does something different to what is expected by defaukt, or Exim’s behaviour 
changed somewhere after 4.86/4.87 (still trying to pinpoint that) but I can’t 
see or replicate the issue.

Puzzled, perplexed… and given that this has only just been raised, I’m even 
more puzzled by it. There must be receivers out there who have insanely strict 
validation policies who would have seen this before!

Graeme
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[exim-dev] dnsdb lookup question

[Graeme Fowler via Exim-dev]

Howdy all

Today's "out of my depth" question relates to the dnsdb lookup.

I have a requirement to specify a nameserver for a specific query, using dnsdb. 
I don't think I can do that without adding the specific nameserver address to 
/etc/resolv.conf, unless I'm missing some configuration option that's either 
blindingly obvious or ludicrously esoteric. Unfortunately that's not possible 
in the specific situation I'm in.

Am I (missing something) or am I about to head deep into the codebase to work 
out how to extend the dnsdb code?

Ta

Graeme
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Re: [exim-dev] dnsdb lookup question

[Graeme Fowler via Exim-dev]

On 14 Oct 2019, at 12:47, Jeremy Harris via Exim-dev  wrote:
> You're not missing anything.  Exim just uses the system resolver library
> and doesn't currently use any interface to specify a particular
> nameswerver.  I don't even know if there is such an API, and I'd
> suggest not going looking; the resolver interface is IMHO particularly
> badly documented.

Good, I'm glad I wasn't being daft. And thanks for the pointer to "not" :)

> Perhaps there's some perl library that does its own dns lookups, not
> using the system libraries?  That would be an alternate route, assuming
> you're willing to use a ${perl } expansion.

I was trying not to have to go there, but if needs be I will. I'll probably 
wrap Perl's Net::DNS module into a readsocket lookup as I don't have Perl 
functionality in Exim in this environment.

Cheers

Graeme


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Re: [exim-dev] dnsdb lookup question

[Graeme Fowler via Exim-dev]

On 14 Oct 2019, at 14:47, Lena--- via Exim-dev  wrote:
> Or you can use
> ${if match{${run{/usr/local/bin/dig +short @... ...}}}{\N\.\N}}

Indeed, or one of many alternatives; unfortunately I could do without the 
execute overhead. Although our platform has a lot of compute resource 
available, using it to execute dig several tens-of-thousands to 
tens-of-millions of times a day isn't very efficient. Hence the readsocket idea 
- execute overhead is at startup time, everything else is 
connect->query->response.

Graeme
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Re: [exim-dev] GDB step by step exim

[Graeme Fowler via Exim-dev]

On 16 Jul 2020, at 05:07, Dennis Roellke via Exim-dev  wrote:
> I’d like to understand better how exim processes EHLO messages. Ideally, I 
> could use gdb to set a breakpoint and step through from wherever I want. 
> Unfortunately, exim just ignores any breakpoints... it hits them for sure, bc 
> I see the print stmts. It must have to do with exims threading. I tried 
> detach-on-fork off,  but no luck.
> 
> Please help: HOW TO DEBUG EXIM?

https://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_exim_command_line.html

See the "-d" section, also "debug_print" in 

https://www.exim.org/exim-html-current/doc/html/spec_html/ch-generic_options_for_routers.html
https://www.exim.org/exim-html-current/doc/html/spec_html/ch-generic_options_for_transports.html

What is it that you're attempting to understand, specifically? The code is 
open, of course, so you can step through that if you need to but note that 
different configurations will process data in different ways according to local 
preference/necessity.

Graeme

PS you probably want to subscribe to the list before posting again so we don't 
have to check and release your messages from the moderation queue.
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Re: [exim-dev] Are bug system emails to exim-dev moderated or slow ?

[Graeme Fowler via Exim-dev]

On 15 March 2023 09:17:07 Jeremy Harris via Exim-dev  wrote:

On 14/03/2023 08:17, Andrew C Aitchison via Exim-dev wrote:

Are these messages moderated

Yes.  Blame spammers.


Quite. There are occasional spates of link spam in Bugzilla, so to prevent 
clogging the list with them and then having to resubscribe people who get 
kicked out because their antispam system rejects the emails, updates from 
Bugzilla are indeed moderated.


I usually process the queue once per day. Sometimes it may take longer than 
that though.


Graeme
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