Mail problem

Hello.

I had an "old" (but still working) iMac 10.4.11. Now working also with a macbook (small & white) 10.5.8.

I transfered all form one to the other by "migration"

Now, all is ok, working fine with both, excepted mail. 10.5.8 doesn't recognize it and have to use entourage Mac. Problem is that when I want to share a movie (quicktime to Mail) as mail not working, it's impossible.

How to recover a good & working mail for my 10.5.8 ? Tried to uptodate, vainly.

Thanks for helps.

JP