Unified Communication (where your fax, voice, email, instant messaging and whatever else are all combined) is being championed by Microsoft, Avaya, Cisco and other companies. For now, UC is what many larger companies are looking towards.
However, smaller businesses, as they traditionally do with technology, will take longer to embrace unified communications to its fullest extent. It also of course depends on the technographic mindset of the small business. Business owners with a "mom-and-pop" mindset (no one reading this), with no desire or mind-set for growth or enhancing the productivity of their business, won't look to united communication and advanced telephony options - ever. But those who are on a trajectory of growth will always look to technologically evolve their business.
If Unified Communication is something you might want to look into Unision has a server and client offering which combines four servers into one. Based on Linux (on the server side), and a Windows based Unison Desktop, Unison provides a single application for communications. It combines not only email, contacts and calendars, but also telephony, instant messaging and Unison Intelligent Presence - real-time free/busy status based on a user’s current activity. All messages, chats and voicemail are accessible and searchable - and all conversations take place within this application.
At this time pricing is not yet announced but Unison will cost less than MS Exchange and Outlook -- while at the same time being much more powerful, according to a Unison spokesperson. They added, "Unison will cost FAR less than Microsoft's full 'unified communications portfolio' of software, which has functionality similar to Unison."

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