[exim] A bunch of documentation bug reports from Debian

>   2. Lists of domains, hosts, and email addresses can contain lookup
>      requests as a way of avoiding excessively long linear lists. In
>      this case, the data that is returned by the lookup is often (but
>      not always) discarded; whether the lookup succeeds or fails is
>      what really counts. These kinds of list are described in chapter
>      "Domain, host, address, and local part lists".

>   2. Lists of domains, hosts, and email addresses can contain lookup
>      requests as a way of avoiding excessively long linear lists. In
>      this case, the data that is returned by the lookup is often (but
>      not always) discarded; whether the lookup succeeds or fails is
>      what really counts. These kinds of list are described in chapter
> >>   "Domain, host, address, and local part lists".

>   [...]
>     The first uses a string expansion, the result of which must be a domain
> >>  list.  String expansions are described in detail in chapter "String
> >>  expansions". The expansion takes place first, and the file that is
>     searched could contain lines like this:

>     [...]
>     when batched SMTP is in use. A full description of the batch SMTP
>     mechanism is given in section "Outgoing batched SMTP" in chapter "SMTP
>     processing". The "lmtp" transport does not have a "use_bsmtp" option,
>     because it always delivers using the SMTP protocol.

>     If this option is set true, the "pipe" transport writes messages in
>     `batch SMTP' format, with the envelope sender and recipient(s) included
>     as SMTP commands. If you want to include a leading HELO command with
>     such messages, you can do so by setting the "message_prefix" option.
> >>  See section "Outgoing batched SMTP" in chapter "SMTP processing" for
>     details of batch SMTP.

>         log_fail_output (pipe) option
>         log_output (pipe) option

>    * If (after expansion) a pattern starts with `^', a regular

>    * If a pattern is not one of the above syntax forms, that is, if a

>      The lookup may be a partial one, and/or one involving a search for
> >>   a default keyed by `*' (see section "Default values in single-key
> >>   lookups" in chapter "File and database lookups"). The local part
>      patterns that are looked up can be regular expressions or begin
>      with `*', or even be further lookups. They may also be
>      independently negated. For example, with

> Do
> $ info exim4
> goto the Concept Index
> put the cursor on e.g.,
> * customizing: Received header:          receive_timeout.
> * customizing:`cannot route' message:    cannot_route_message (router).
> and hit RET. One gets an error that it can't go to ....

>     ...

>     status of the message includes a list of recipients who have already
>     received the message. The format of the first spool file is described
> =>  in chapter "Format of spool files".

>     Address rewriting that is specified in the rewrite section of the
> =>  configuration (see chapter "Address rewriting") is done once and for
>     all on incoming addresses, both in the header lines and the envelope,
>     at the time the message is accepted.  If during the course of delivery
>     additional addresses are generated (for example, via aliasing), these
>     new addresses are rewritten as soon as they are generated. At the time
>     a message is actually delivered (transported) further rewriting can
>     take place; because this is a transport option, it can be different for
>     different forms of delivery. It is also possible to specify the
>     addition or removal of certain header lines at the time the message is
> =>  delivered (see chapters "Generic options for routers" and "Generic
>     options for transports").

>     This chapter describes the generic options that apply to all routers,
>     identifying those that are preconditions. For a general description of
> >>  how a router operates, see sections "Running an individual router" in
> >>  chapter "How Exim receives and delivers mail" and "Router
> >>  preconditions" in chapter "How Exim receives and delivers mail". The
>     second of these sections specifies the order in which the preconditions
>     are tested.  The order of expansion of the options that provide data
>     for a transport is: "errors_to", "headers_add", "headers_remove",
>     "transport".