3Com Corp yesterday announced the availability of free software that will enable users of its Palm Pilot handheld computer to send and receive emails, access schedules or download corporate- based applications remotely using a mobile phone. The networking giant said the software, called Enhanced IR (infra red), is designed to work with Ericsson9s infrared-capable mobile phones, including its 888 series. Users of its PalmPilot professional edition or Palm III organizers can download the software for free from www.palm.com or from mobile.ericsson.se.