Sprint Nextel’s Instinct smartphone can now access corporate calendars through Microsoft Exchange and IBM Lotus Notes. The access is part of Sprint’s Mobile Email Work service, based on technology from Seven.

“Mobile Email Work with corporate calendar synch includes monthly, weekly and daily views of the user’s calendar, along with an appointment view that displays the details about each appointment or meeting. Reminders bring upcoming appointments or meetings to the user’s attention. Users can edit existing appointments, accept or decline meeting requests, or create new single-date, multi-date or all-day appointments,” Sprint explained in a statement today.

“Users also can delete appointments and meetings. All changes made on the Sprint phone are automatically synchronized with the user’s desktop calendar,” and the service will be available for unspecified other handsets in the future, officials added.

The calendar feature coincides with Maintenance Release 4, which added long-awaited support for standard text entry in Java programs, support for native document viewing in .doc, pdf, .ppt and other formats, along with fixes for 50 open ticket items.

More news about Sprint’s smartphones is expected at next week’s developer conference.