Currently, mew-x-mailer includes "Emacs 27.1", "Emacs 28.0" for
Emacs 27.1.90, 28.0.50.
Expected results are "Emacs 27.1.90", "Emacs 28.0.50".
Note that emacs-version no longer includes the build number since
Emacs 26, so emacs-build-number should be checked for Emacs 24 and 25
to use emacs-version.
Currently, mew-x-mailer includes "Emacs 27.1", "Emacs 28.0" for Emacs 27.1.90, 28.0.50.
Expected results are "Emacs 27.1.90", "Emacs 28.0.50".
Note that emacs-version no longer includes the build number since Emacs 26, so emacs-build-number should be checked for Emacs 24 and 25 to use emacs-version.
cf. https://git.savannah.gnu.org/cgit/emacs.git/tree/etc/NEWS.26#n300