Possible Clues:

• Slot in a door
• DVD format
• Mail holder
• Spooner wanted improved security for this door feature
• Allow her to get the post there of using her fists, by the sound of it
• By the sound of it, allow her to fight in mail
• By the sound of it, allow her to get the post in the ring
• Sounds as if we'll have to allow her into the ring for the post
• Wide-screen viewing method
• Allow her to be in the ring, by the sound of it, though it's all male there, by the sound of it (6, 3)