Can a lady give a Shiur to men?
I run a lunch and learn in my office, the crowd is mixed and diverse, and we bring different speakers every week. It was suggested from our main sponsor to have a lady (who is fully Frum and Tznius) to give the Shiur/lecture. Is this permissible? Obviously, I am in a sensitive position. If the answer is in the negative, I would need to present it to the local rabbinic authority, and present the sources in Halacha.
This is not proper for a religious crowd. Poskim advise against this. (Men need to look at the speaker, and to have men looking at a woman speak for a long period of time is not Tznius. We find in the Poskim that by the age of 9, it is important to have only male teachers).
Some poskim even forbid it outright.
(See Shaarei Yosher III: 21. Shevet Halevi 3:14. Mishnah Halachos 5:218. 11: 58. L’horos Nasan 1 EH 60:5. Igros Moshe OC 5: 12. See also ibid. 2:36).
However, if the crowd is not religious, and the purpose is to teach them Torah, there could be some room for leniency in very specific scenarios, and one should seek guidance from a Rav.