Two Pronged Question Regarding Mac Mail/ Thunderbird


I have a new mac ibook with tiger and just upgraded. mac mail is sloooooow, freezes, takes forever, doesn't download the message ect. i have a very long, complex imap account that is necc to maintain and this didn't prove a problem so frequently before the 'upgrade'.

1. can anything be done to speed up/fix/ alter the
might the mail.appetizer or mail.tag utilities have anything to do with this (slowness started way before i imported them)

2. in lieu of this, I would use thunderbird if i could import my mac address book. I've used the "address book exporter" and can't seem to get the fields to enter correctly or correspond, and so i am loathe to start over in t-bird because i have 1000 contacts. Any suggestions on how to get that to work?

2 1/2, In lieu of these---any other mail apps i should turn to