As Michael says see Darell Mays contrib which is here
myezserver.com/support/contribs/xxx
smeserver-twig-2.8.3-2dmay.noarch.rpm
This is not Twiggi but Twig which has gained some features and lost some over the previous Twiggy
It does work in SME 7 however.
to install downlaod the rpm and use
rpm -Uvh smeserver-twig-2.8.3-2dmay.noarch.rpm
make sure you have enabled webmail in server-manager
check the time.date and time zones are the same on server and PC's
good luck