Tech Specs

Explore the core technologies
behind Backstage.

Backstage Mail

Backstage offers world-class email that works with any OS, just about any app, on just about any device. And our webmail client is feature-packed if you want to keep things simple.

User Friendly

Emails and Notes

  • Custom Signature Article
  • Distributed mailing lists Article
  • Domain footers Article
  • Delegation Article
  • Public and shared folders Article
  • IMAP, POP3 and EWS protocol support
  • Multiple email addresses per user
  • Email aliases
  • Out of Office messages
  • Message filters and rules
  • User managed spam whitelist
  • Delivery and read receipt
  • Multi-language support
  • Full text search
  • Desktop notifications

Calendars and Tasks

  • Public and shared calendars Article
  • Delegation Article
  • Synchronization (CalDAV and EWS)
  • Privacy flag
  • Scheduling and response tracking
  • Recurring events with exceptions
  • Reserve conference rooms/resources
  • Labels
  • Free/Busy assistance
  • Reminders
  • Travel time
  • Comment on invitation replies
  • Print view
  • Agenda view
  • Tasks with reminders
  • Search
  • Desktop notifications


  • Synchronization (CardDAV and EWS)
  • Remote lookup (LDAP)
  • Public and shared contacts
  • Global address list
  • Create contact from email
  • Contact groups
  • Contact photos
  • Click to Call with Kerio Operator

Instant Messaging

  • Web based chat Article
  • Jabber/XMPP protocol support Adium ChatSecure
  • Group chat
  • Chat rooms
  • Presence
  • File transfer
  • Global address list with photos
  • Desktop notifications


  • Exchange ActiveSync 14.1
  • CalDAV/CardDAV/IMAP client support
  • Kerio Connect Sync app for Android
  • Global address list synchronization
  • Public and shared folders
  • Automatic configuration for iOS


  • Microsoft Outlook iOS Windows Android macOS
  • Apple Mail, Calendar, Contacts, Messages, and Reminders iOS macOS
  • Android Mail Article
  • Windows 10 Mail and Calendar
  • Kerio Connect Client (web based)
  • Kerio Connect Desktop App technology Preview (Mac)

Admin Friendly

Server Management

  • Remote web based administration
  • Administration API
  • Customizable login page
  • One-click software updates
  • Automated server backup
  • Multiple domains
  • Custom logo per domain
  • Distributed domains
  • Storage quotas and notifications per domain
  • SMTP server relay routing (smart host)
  • Email archiving per server and per domain
  • Moderated mailing lists with NNTP
  • Recover deleted items
  • Status, activity, and debug monitoring
  • Audit logs, charts, reports, and statistics


  • Password policy with complexity
  • Password guessing protection
  • Secure connectivity (TLS 1.2)
  • Require secure connectivity
  • Perfect Forward Secrecy support
  • Signed and custom SSL certificates
  • Encrypted email (S/MIME)
  • DKIM signatures
  • SMTP submission
  • Directory harvest attack protection
  • Sender anti-spoofing protection
  • Remote mobile device wipe

Content Filtering

  • Integrated anti-virus
  • Standard spam filter (SpamAssassin with SURBL)
  • Advanced spam filter: Kerio Anti-spam (powered by Bitdefender)
  • Spam repellant (SMTP greeting delay)
  • Internet and custom blacklists
  • Greylisting
  • Anti-spoofing (SPF)
  • Attachment filtering
  • Server based filtering rules
  • Message size limits

User Management

  • Microsoft Active Directory
  • Apple Open Directory
  • Linux PAM
  • Local user database
  • Import user list
  • Account settings templates
  • Mailbox quotas and notifications
  • Access policies based on protocols
  • Data retention policy (Items clean-out)

Backstage Files

Your files, stored safely in our cloud, available from anywhere, in sync across all your devices, and backed up so you don’t have to.

Backstage Office

  • Create and edit complex documents in native MS Office format
  • Word Processor
  • Spreadsheets
  • Presentations
  • Use various styling and formatting tools
  • Insert and manipulate objects
  • Real-time collaboration with other users
  • Change tracking
  • Document comparison, change acceptance, change merging
  • Export to PDF
  • File versioning
  • Use any modern web browser
  • Download native apps for Windows, Mac, Linux, iOS, and Android


  • Share to other users’ ownCloud Article
  • Share to non-users via URL Article
  • Password protection
  • Link expiration
  • Anonymous sharing
  • Full access sharing
  • Admins can track and audit sharing activity


  • Sync files between desktop, mobile, and the web Article
  • Shared files and folders sync between all associated users
  • Active file change monitoring
  • Pushes latest versions to all devices

File Handling

  • File backup and restore Article
  • Upload and download files on any device iOS
  • Universal file access
  • Support for external storage (direct-attached, network-attached, virtual, other cloud-providers)
  • Favourites
  • Tagging
  • File ownership transfer


  • SSL
  • Customizable encryption
  • SSO/SAML 2.0 authentication
  • Unshared files are completely private
  • User-level and file-level restrictions can be set by admins
  • Virus scan
  • Admins can track and audit account activity