Exchange administrators should relay a message to their Apple iPhone iOS 4.0.0 users that unless they update their devices by July 29 they will lose access to Exchange Online-based email and calendaring.

Apple released an update for the iPhone iOS 4.0,0 operating system this week to fix serious performance issues with Exchange ActiveSync (EAS) that caused heavier than normal loads on servers and sync issues with email, calendar, and contacts.

Mike Crowley, an Exchange administrator for a major U.S.-based Microsoft integration company, said every Exchange deployment he has done recently, from Exchange Server to Exchange Online via the Business Productivity Online Suite (BPOS), has included iPhone users in some capacity, so this is an important update.

Apple published a workaround July 1 to improve syncs between iOS 4.0.0 and EAS and increase server performance, but Exchange admins needed a true fix to those problems and other email related issues.

Apple made update (4.0.1) available this week for users with the iPhone 3G, 3GS and 4 devices running iOS 4.0.0 which includes the configuration patch needed for iOS4 devices to use Exchange ActiveSync with Exchange Online.

With that, Microsoft is requiring users with those devices to update to iOS 4.0.1 by July 29, 2010. After that date, users who haven't updated to iOS 4.0.1 won't be able to connect to Exchange Online using Exchange ActiveSync to send and receive email and synchronize message and calendar items, Microsoft said on its blog.

This only affects users with devices running iOS 4.0.0, so previous versions of Apple iOS won't be impacted, according to Microsoft.

Original article by Bridget Botelho, Senior News Writer at SearchExchange.com