Possible Clues:

• Delay office party's beginning to hour after noon
• Put stamps on the 26 down and put it off with the soft one
• Reschedule for later
• Delay when mail has broken open
• Put off by all the letters from open organisation
• Shelve mail -- possibly open later
• Put off till later
• Set aside
• Mail to open after moving delay
• After quiet over, new English opener is to 1