Since finding out there was a native Lotus Notes client for Linux, I've been tinkering and trying to get it to work on a whole host of distros. A lot of the problems you will encounter are because of missing dependencies.

I've posted a link to my webpage, with the instructions on what you need to do to get this client working (if you have it).

Installing the Lotus Notes 7 Native Client in Linux

There is every chance that this will work with versions of Mandriva prior to 2007.1 (spring), but you can easily try this, providing you have the most important openmotif or libtiff in it's place with a little bit of extra work symlinking to fool the system.