Comparisons anchored on Open-Xchange OX App Suite, the email and groupware suite built for service providers.
Replacing an email and groupware suite: OX App Suite aimed at hosting providers with AGPL source mirrors against Zimbra 10, which needs a license key and ships no ready FOSS packages, compared on licensing risk, scale, migration effort and who supports each.
A white-label suite for hosting providers against an Exchange drop-in with native Outlook MAPI/HTTP, EWS and ActiveSync: licensing, partner-only pricing, Outlook fit and Exchange migration tooling.
A full provider-grade suite against a lightweight groupware layer on existing IMAP and SMTP servers: webmail, calendars and ActiveSync, Outlook support, licensing and who runs each at scale.
What Dovecot 2.4 removed from the free edition (replication, Director, fts-lucene) and what Open-Xchange's Dovecot Pro offers instead with its Palomar cluster architecture and vendor support, for mail platforms deciding how to scale IMAP.
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