Anonymous letter. Sender requested to make himself known

Whereas a Proposal, Sign'd A. R was lately sent to the Right Honourable the Lord High Treasurer of England, for the Improving Her Majesty's Revenues arising by the Penny-Post: Her Majesty's Post-Master General, by the Direction of the Lord High Treasurer, doth hereby give notice, That if he will attend the said Post-Master General, and make good what he offers therein, he shall have all fitting Encouragement and a suitable Reward.