Related Clues:

• Bugle call
• Taps, in the British military
• Bugle call sounded at sunset
• Military bugle call at funerals and sunset
• Bugle call for sunset or funeral
• Military bugle call at sunset and funerals
• Army bugle call at sunset and funerals
• Military bugle call sounded at sunset
• It's played at bedtime in the army
• It sounds of late as if there'll be no more mail
• No more mail, and no more light, when that's blown
• The final blow is that's no more mail
• By the sound of it, it's something one might find in 32 across
• It sounds as if there's no more mail after 18 down
• That's the final Evening Mail on the blower