I just downloaded the latest Seamonkey 2.0.12 SRPM from Mandriva cooker and rebuilt it on my Mageia VM and it built flawlessly, I only had to remove all the obsolete "%if %mdkversion" sections, but all dependecies are available in Mageia. So technically importing Seamonkey into Mageia seems straightforward, the only issue is licensing (as for Firefox).
Christiaan I'm a newbie packager here at Mageia so personally I'd much prefer if you maintain this package for Mageia, it looks far too complex for me. :) -- Mageia ML Forum Gateway: http://mageia.linuxtech.net/forum/