GALsync

GALsync by NETsec is a well-established integration solution designed to synchronize Global Address Lists across multiple Active Directory forests, helping organizations operate as if they share a single directory environment. Widely used in large enterprises, government agencies, and managed service providers, the software enables seamless sharing of contacts, groups, and calendar availability between separate Exchange infrastructures without requiring trust relationships between forests, which strengthens security and simplifies deployment during mergers or multi-tenant operations. Built on .NET managed code and optimized for 64-bit Windows environments, GALsync delivers reliable performance through efficient delta synchronization that transfers only directory changes rather than full datasets, reducing bandwidth usage and processing time. Its functionality includes granular object selection, multiple secure data transfer options such as FTP, shared directories, and encrypted email attachments, as well as a ContactSync module that allows GAL entries to appear in users’ personal mailbox contacts for easy access on mobile devices. The software integrates smoothly with various Microsoft Exchange environments including legacy versions and modern hybrid setups involving Microsoft 365.