Possible Clues:

• End post of stair rail
• Fresh letter-opener applied to back of envelope, for domestic post
• Latest deals oddly missing in column
• One welcomes receiving post
• Sounds like a strange letter in the post
• Staircase feature
• Spiral staircase pillar
• Top/bottom supporting post of a stair-rail
• English lecturer's first to go after recently instituted post
• Stair part