Alternativa shdlr.comu za Microsoft Exchange Server z licenco odprtokodnega vira

• Microsoft Exchange Server
  Vse platforme Windows Mac Linux Chrome OS Android iPhone Windows Phone iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) jQuery Windows Mobile Slack Microsoft Office Outlook Chrome Google Calendar Drupal Google Apps Microsoft Exchange Server Apple Calendar
• Open Source licenca
  Vsako dovoljenje Brezplačna licenca Open Source licenca Trgovsko dovoljenje