The postal market is one of the oldest if not the oldest network industry. After centuries of private and public postal monopolies, the EC aims to liberalize the mail market entirely whilst safeguarding the Universal Postal Service. Based on Swiss Data, the book first identifies the main drivers of mail volumes and draws special attention to "e-substitution", one of the major challenges of the postal industry. The book then assesses the most important cost characteristics of the postal market. In the core of the book, the main regulatory market models are described, modeled, and analyzed on their price and welfare implications. The last part of the book focuses on the two- sidedness of the postal market, an issue that will be crucial for successful long term regulation of the sector. In doing so, the book outlines the main regulatory challenges of the industry. For the Swiss case, it addresses the key issue whether a full market opening of the Swiss mail market is economically desirable given the current level of universal service obligations in Switzerland.