Hello Robert,
if I find the time, I make a patch ready. It shouldn't be to hard. The
problem is that mutt doesn't use open64, lseek64 or the corresponding
function on other architectures. Maybe it is as easy as to enable 64bit
offsets (I saw that once for IMAP?!).
Just out of curiosity: Who long took it to open the 2Gbyte mbox before
it reached the magic border?
Thomas