CardDAV in Microsoft environments: Reliably synchronize company contacts on end devices

The modern alternative to ActiveSync for GAL, Outlook, Entra ID, and Exchange contacts

The management and provision of company contacts in Microsoft environments is an ongoing issue for IT departments. While Exchange, Entra ID (Azure AD), Active Directory, and Outlook serve as central directory sources, the synchronization of these contacts often fails at one crucial point: reliable transfer to mobile devices.

For many years, ActiveSync was the standard for transferring company data, including contacts, to iOS and Android devices. However, ActiveSync quickly reaches its limits, especially with larger company address books, in heterogeneous device landscapes, and when synchronizing to multiple users.

The solution: CardDAV – a stable standard that is becoming increasingly important in Microsoft environments.

Table of contents:

• Why CardDAV is so relevant in Microsoft environments

• CardDAV as a missing component in Microsoft environments

• sync.blue® MOBILE Storage: Provide Microsoft contacts as CardDAV – optionally with MDM distribution

• The advantages of sync.blue® MOBILE Storage

• Conclusion: CardDAV + sync.blue® as the modern standard for mobile business contacts

Why CardDAV is so relevant in Microsoft environments

CardDAV is a standardized protocol for providing and synchronizing contacts via the web. Unlike ActiveSync, which is heavily dependent on the behavior of the respective end device, CardDAV works on the server side and is contact-focused. This makes it ideal for companies that need to reliably distribute large and changing company address books.

CardDAV is:

• Contact-centric and optimized for this purpose

• Independent of the operating system behavior of the devices

• Stable even with large GALs and many end devices

• suitable for 1-to-many scenarios (e.g., one GAL for many users)

• ideal for company-wide, consistent contact data

This makes CardDAV ideal for distributing Outlook, GAL, Entra ID, or Active Directory contacts to mobile devices in a structured, uniform, and reliable manner.

CardDAV as a missing component in Microsoft environments

Microsoft provides central contacts via Exchange, Outlook, Entra ID, and Active Directory. These systems are well integrated within the Microsoft ecosystem, but do not offer a CardDAV endpoint that mobile devices can use directly. This means that companies lack a standardized way to distribute company contacts in a contact-optimized, server-side, and device-independent manner.

This is exactly where sync.blue® comes in.

sync.blue® MOBILE Storage: Provide Microsoft contacts as CardDAV – optionally with MDM distribution

sync.blue® MOBILE Storage forms the central interface between Microsoft directory services and mobile devices. Mobile operating systems such as iOS and macOS support CardDAV natively – without additional software installations or user actions.

Devices can connect directly via CardDAV. Alternatively, MDM and UEM systems such as Microsoft Intune, Jamf, MobileIron, or other platforms can be used to automatically deploy the configuration to all smartphones. This creates a fully automated and centrally controllable deployment path.

How it works:

The advantages of sync.blue® MOBILE Storage

sync.blue® MOBILE Storage is based on a fully server-side and controlled synchronization logic. Changes from Exchange, GAL, Entra ID, or Active Directory are centrally recorded and provided as uniform CardDAV data records. End devices then access this consistent data set without having to execute complex or device-dependent processes themselves.

This allows companies to benefit from:

• Zero-touch setup: automatic provisioning without user intervention

• Fast, incremental synchronization: ideal for large, frequently changing address databases

• Native integration: the company address book appears directly in the iOS/macOS contacts app

• Offline availability: contacts are also available without the internet

• Reliable caller ID: clean number formats ensure unique caller ID on mobile devices

• Read-only contacts: protects data quality and prevents unwanted changes

• ISO 27001-certified & GDPR-compliant hosting: in German data centers of independent providers

• Automatic photo sync: Employee photos are transferred and displayed in contacts on mobile devices

Conclusion: CardDAV + sync.blue® as the modern standard for mobile business contacts

CardDAV provides the missing technological bridge in Microsoft environments: a stable, contact-optimized way to reliably transfer company contacts to mobile devices. In combination with sync.blue® MOBILE Storage, this creates a modern, centrally controllable, and scalable solution that neatly structures GAL, Outlook, Entra ID, and AD contacts and automatically makes them available on devices.

For companies that need future-proof, secure, and consistent mobile contact provisioning, CardDAV with sync.blue® is the ideal solution.

Try sync.blue® now for free and finally synchronize Microsoft contacts reliably.

Try sync.blue® now for free

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About sync.blue®

sync.blue® is the leading tool for seamless synchronization of contacts across more than 80 applications and devices. The cloud solution offers both one-way and two-way synchronization and ensures efficient contact management. sync.blue® impresses with its extensive compatibility with numerous apps and relies on the highest security standards, including GDPR guidelines. The service is hosted in German data centers, which also contributes to data security.

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