Author: Jeremy Harris Date: To: exim-users Subject: Re: [exim] treating moral config errors as serious
On 18/07/2019 21:00, Julian Bradfield via Exim-users wrote: > On 2019-07-18, Jeremy Harris via Exim-users <exim-users@???> wrote:
>> On 18/07/2019 20:03, Julian Bradfield via Exim-users wrote:
>>> I've just had an embarrassing incident where a system upgrade
>>> overwrote a customized greylistd, with the result that mail from new
>>> senders was always deferred because of an invalid condition value, and
>>> I didn't notice for more than a week.
>>
>> What sort of "invalid value" ?
>
> "white", "grey" (instead of the "true" or "false" that would have been
> correctly emitted by the customized greylistd).
Depending where you use strings indicating truth values,
the interpretation varies. Router conditions have a lax
interpretation: "false" "no" and "0" are false, anything
else is true. So "grey" would be true.
In others, eg. ACL conditions, tighter rules apply.
Specifically, for ACLs, you get a defer. This is
documented.
We're unlikely to change those rules; it would break
valid configurations.
