Possible Clues:

• One receiving election leaflets, say, designed specially to treble vote
• Postholder?
• Format for presenting films in video form
• Recipient of post and I, for instance, fight
• Format a film so as to preserve the original widescreen cinematic format
• 'For the post. Allow her to be in the ring, by the sound of it (6,3)'
• Slot in a front door
• More security provided for Spooner's door, and feature of it?
• Allow her to be in the ring, by the sound of it, by post
• By the sound of it, allow 'er to be posted - and pasted, perhaps, in the ring