Is congregational prayer valid for women following a male imam in an office surau when the divider between them is fully covered by a long curtain, and is the congregational reward obtained?

Summary

For prayer outside a mosque, the Shafi'i school requires that no barrier block the view of the imam, and a thin curtain or one slightly open so the imam can be seen does not affect the validity of the congregational prayer. If a thick curtain is closed so tightly that the imam cannot be seen at all, following the imam in congregation is invalid. In that case the woman's prayer is nullified if she waits for the imam for a long time, but if the wait is short her prayer remains valid as an individual prayer without the congregational reward, while the muqabil asah view holds that it is not nullified but counts as an individual prayer. The fatwa advises against curtains that block women's view of the imam in order to avoid scholarly disagreement, unless the gazetted surau has the ruling of a mosque, in which case the curtain does not harm the congregational prayer.

Written in our own words from the original fatwa — check the source before acting on it.