Version:           1.8.3 (using KDE KDE 3.4.3)
Installed from:    Gentoo Packages
Compiler:          gcc version 3.4.4 (Gentoo 3.4.4-r1, ssp-3.4.4-1.0, pie-8.7.8) Configured with: /var/tmp/portage/gcc-3.4.4-r1/work/gcc-3.4.4/configure --prefix=/usr --bindir=/usr/i686-pc-linux-gnu/gcc-bin/3.4.4 --includedir=/usr/lib/gcc/i686-pc-linux-gnu/3.4.4/include --datadir=/usr/share/gcc-data/i686-pc-linux-gnu/3.4.4 --mandir=/usr/share/gcc-data/i686-pc-linux-gnu/3.4.4/man --infodir=/usr/share/gcc-data/i686-pc-linux-gnu/3.4.4/info --with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/3.4.4/include/g++-v3 --host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --disable-altivec --enable-nls --without-included-gettext --with-system-zlib --disable-checking --disable-werror --disable-libunwind-exceptions --disable-multilib --disable-libmudflap --disable-libgcj --enable-languages=c,c++,f77 --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu Thread model: posix
OS:                Linux

When receiving mails send to a large number of people in To or CC it would be nice to be able to collapse those receivers. Especially on small screens this would largely improve the usability when reading those mails.
(Yes I know those mails should not be sent, but convincing a large organisation can be very difficult)