Sheikh `Abd al-Wahhâb al-Turayrî, former professor at al-Imâm University in Riyadh
It is permissible to hold classes in the mosques for women, even if the instructor happens to be a man. It is permissible for men to speak to women, for women to speak to men, and for them to ask each other legitimate questions.
This took place in the prophet’s Mosque with the Prophet (peace be upon him) himself, and there was no partition in place. There are numerous authentic hadîth that extablish this practice
For instance, Abû Sa`îd al-Khudrî relates in Sahîh al-Bukhârî (101) and Sahîh Muslim (2633):
The women one day complained to the Prophet (peace be upon him): “The men get most of your time. Give us a day to meet with you.”
So the Prophet (peace be upon him) promised to set aside for them a day when he would meet with them to impart to them religious teachings and instruction.
Al-Bukhârî records this hadîth in his Sahîh under the heading “Should Women be Given a Speacial Day for Receiving Knowledge”
Therefore, holding classes for women in the mosque is certainly permissible, even if there are male instructors. However, it is important to stress to the attendees that they should observe proper Islamic dress and that they must avoid beautifying themselves and wearing perfume.
And Allah knows best.
Source: Islam Today