Bold font in Sent listing

[David Woodfall]

I find some mail entries are bold in 'Sent' and some not, but I can't
find any reason why they should be.

set index_format="%3C %Z %[!%d/%m/%y] %-20.20t      %s"

Anything it that that would cause bold fonts?

I'd rather not have them if possible.

D.