After 10 years of development the Dovecot IMAP server is now a benchmark in terms of stability, range of features and performance. Whether you need a single IMAP server for small user groups, a cluster system with high availability for enterprises with several thousand employees, or a complex infrastructure with directors, caching proxies and active/active setups for Internet Service Providers, Dovecot offers concepts and solutions for all kinds of requirements without becoming too complex. Based on extensive experience of many Dovecot projects, this book supports administrators during the conceptual design phase, helps avoid errors and strategically wrong decisions, and shows how to implement different configurations by means of concrete and reproducible instructions.