Facility services giant ISS has revealed plans to bring 25,000 staff worldwide on to the hosted email component of Microsoft's Office 365.
The Danish company had more than half a million employees, including 22,000 in Australia.
Most were not desk-bound but involved in facility services such as reception, cleaning, mail delivery, grounds and building maintenance.
ISS' global IT buyer Morten Wagner said that Exchange online would replace Exchange on-premises, Lotus Notes and lesser-known systems.
About 8000 staff were migrated to Exchange Online. The remaining 17,000 – sitting in offices in 44 countries – would follow later this year.
Microsoft launched its Office 365 cloud service this week, for which
Australian user will pay substantially more than users in other countries for the cloud service Microsoft issued this week.