I've got a sub folder setup for a specific email account. Email is
diverted to that sub folder via a mail rule. The trouble is when I try
to reply to emails that reside in the sub folder, the replies are not
sent, they are simply placed in the same sub folder in which the
original email resides.

In order to reply, I have to move the emails to my root inbox and reply
from there...does anyone know how to fix this?

Thanks,
Kristan