smeserver-twiggi-1.10.16-4.noarch.rpm, yes, 6.x set in options, but webmail was disabled, because i try to use twiggi on a serveronly 6.0.1 machine. Thanks for suggestions guys, will report back if webmail-enabling has helped.
... no
Uninstall, reinstall.
... no, keeps old values.
... i must be daft: chown -R www:www /opt/groupware/twiggi.