Google's enterprise Gmail offering now presents a viable alternative to Microsoft Exchange Online, according to analyst firm Gartner.
Gmail has been building momentum with enterprises with more than 5,000 users since it entered the cloud email market five years ago.
"While Gmail's enterprise email market share currently hovers at around 1 per cent, it has close to half of the market for enterprise cloud email. And while cloud email is still in its infancy, at between 3 and 4 per cent of the overall enterprise email market, we expect it to grow to around 20 per cent of the market by year-end 2016, and 55 per cent by year-end 2020," Cain added.
Gartner suggests that Novell's GroupWise and IBM's Lotus Notes have lost momentum in the enterprise market in recent years, and this has made room for Google to prosper.
However, if Google wants to achieve contract wins from organisations that have complex requirements, such as large financial institutions, then it needs to be more transparent about its back-end features, according to Gartner.
Large system integrators and enterprises report that Google does not share details around its continuity, security and compliance.
Gartner also highlights the fact that it will be difficult for other vendors to penetrate the market because of the intense competition between Microsoft and Google.
"Microsoft and Google being so competitive will make both vendors stronger," said Cain. "However, the rivalry will make it difficult for other suppliers to compete directly in the cloud email and collaboration space."