Ratuus is described as 'RATUUS is an easy to use, web based system for administration of POSTFIX virtual domains and users' and is an app in the Network & Admin category. There are six alternatives to Ratuus for a variety of platforms, including Linux, Online / Web-based, Mac, Self-Hosted solutions and Windows. The best alternative is Lightmeter, which is both free and Open Source. Other great apps like Ratuus are Modoboa (Free, Open Source), Postfix Admin (Free, Open Source), Jam.py Postfix Aliases (Free, Open Source) and ViMbAdmin (Free, Open Source).
Møil is an open source administration user interface for database backed mail servers (postfix/dovecot). It brings the handy possibility of managing the database with migrations and a lot of beautiful CRUD.