Possible Clues:

• She takes charge of mail after motorway tension
• Lady of letters' blog taken on by the other woman
• Support film about extremely serious lady of letters
• Blog entry by the other woman having a job sorting the letters
• Position for one of the teachers might apply to woman of letters
• Handles letters for concubine behind pillar
• Office manager showing tension after motorway journey?
• Mail manager's tension after motorway trip
• Local head in mail service