Posts from men and replies to articles are strictly refused.

Literal

Men [from-からの] posts [and-や] articles [to-への] replies [topic-は] completely refuse-[humble progressive-しております].

一切お断りしております 'we strictly refuse' — 一切 'completely, without exception' + お断りする (humble refusal) + ております (humble progressive). レス is clipped from レスポンス 'response.' A forum rule for a women-only space.