Does `a "group" option and adding a "group" option' a meaningless repeatition?

[Andreas Metzler]

On 2023-09-10 Regid Ichira via Pkg-exim4-users <pkg-exim4-users at alioth-lists.debian.net> wrote:
> Quoting /usr/share/doc/exim4-base/README.Debian.gz :

>     If any of your aliases expand to pipes or files or directories you
>    should set up a user and a group for these deliveries to run under. You
>    can do this by setting the "user" and - if necessary - a "group" option
>    and adding a "group" option if necessary. Alternatively, you can
>    specify "user" and/or "group" on the transports that are used.

> I am confused by 

>   You can do this by setting the "user" and - if necessary - a "group" option
>   and adding a "group" option if necessary. 

> Isn't it repeating twice, in a sequence and in the same sentence, the 
> suggestion of adding a "group" option to the router?

A group needs to be defined but it can be done explicitely (group=) or
implicitely by setting user= and using the primary group of the user.

https://www.exim.org/exim-html-current/doc/html/spec_html/ch-generic_options_for_transports.html
group 	Use: transports 	Type: string† 	Default: Exim group

This option specifies a gid for running the transport process,
overriding any value that the router supplies, and also overriding any
value associated with user (see below).

user 	Use: transports 	Type: string† 	Default: Exim user

This option specifies the user under whose uid the delivery process is
to be run, overriding any uid that may have been set by the router. If
the user is given as a name, the uid is looked up from the password
data, and the associated group is taken as the value of the gid to be
used if the group option is not set.

cu Andreas
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