ActiveSync is a Microsoft technology that allows you to synchronize data such as email, contacts, and calendar information between your Windows-based PC and your mobile device. It was previously used for synchronizing data between Windows-based PCs and mobile devices running Windows Mobile operating system.
Unfortunately, ActiveSync is not available for Windows 10. Microsoft has discontinued the use of ActiveSync in favor of its newer synchronization technology, Exchange ActiveSync (EAS). EAS is included with Microsoft Exchange Server and is used to synchronize data between Exchange Server and mobile devices running Windows Phone, iOS, or Android operating systems.
If you want to synchronize data between your Windows 10 PC and a mobile device, you can use the built-in Mail, Calendar, and People apps in Windows 10 to set up email accounts and synchronize your data.
For example, you can set up a Microsoft Exchange, Outlook.com, or Google account in the Mail app and sync your email, contacts, and calendar information. Additionally, you can use third-party synchronization software or services to synchronize data between your Windows 10 PC and mobile device.