bug#53307: 27.2; nnmail-crosspost

[Roland Winkler]

I have been rather confused by mail splitting in Gnus, where my mail was
crossposted to multiple groups, till I realized that the culprit was
nnmail-crosspost that is t by default.  This default is confusing
because the Gnus info page on "Splitting Mail" says

  The first rule to make a match will "win", unless you have
  crossposting enabled.

This lingo suggests to me that crossposting is disabled by default.  One
can debate whether the default of nnmail-crosspost should be t or nil.
Personally, I'd vote for changing the default to nil.  However, if the
default t is kept, I suggest that the above sentence should be changed
to something like

  If multiple rules match (excluding the general ‘""’ group), mail is
  crossposted to all these groups, unless crossposting is disabled by
  binding nnmail-crosspost to nil.


In GNU Emacs 27.2 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2021-06-07 built on regnitz
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Debian GNU/Linux 10 (buster)