ONLYOFFICE - MultiFunctional Office Suite
ONLYOFFICE is a multi-featured open source office suite, that features online document editors, platform for document management, corporate communication, mail and project management tools.
It consists of three parts
Document server is online office suite, which includes editors for texts, spreadsheets and presentations, fully compatible with MS Office and other popular formats. It also offers a lot of collaborating capabilities (real-time co-editing, commenting, reviewing, built-in chat). It can be installed as a part of the ONLYOFFICE system or stand alone and connected to popular cloud storage like Nextcloud, ownCloud, Alfresco, ect.
Community Server collaborative system, which contains project and document management systems, Ghantt chart, CRM, calendar and email aggregator.
Mail Server is a full-featured mail server solution developed on the base of the iRedMail package. it allows you to connect your own domain name, create mailboxes and add aliases for each mailbox.