[Tfug] Which EMail reader for BIG volumes of mail?

[Jim March]

When I mean "big", I mean out past 2gig in a matter of a few days.  I
have somebody who wants to convert who is likely THE biggest EMail
volume user that anybody's ever seen.  And somebody literally famous
enough that if she jumps to Linux, the news will make Digg and Reddit
in a matter of days.

She also need to deal with multiple accounts.  She's on Outlook now.
I'll almost certainly be her them to Ubuntu Intrepid, although Jaunty
in beta is looking SO good right now...

Anyways.  Suggestions welcome.  I know for a fact she'll overload
Thunderbird if we try that!  Would the latest Evolution work, or
should I be thinking of a text-based reader, or...???

Thanks!

Jim