Which synchronization modes are available?

Jonas Hönge

December 19, 2025 14:42 Updated

When creating a connection, an optional synchronization mode can be selected in the Advanced Settings:

Synchronization Modes	Explanation
1. Expand	The default setting for all newly created connections. Contacts are never deleted in the target (even if they were deleted in the source).
2. Mirror	Contacts in the sync target are aligned with the contacts in the sync source. Should only be applied if the sync target is initially empty or contains only contacts from the sync source.*
0. Custom	The Custom mode appears when the current setting does not correspond to any standard mode. This can occur in cases of: Existing connections before the introduction of the standard modes Individual customizations by the sync.blue® service team

*This synchronization mode is only available for selected targets. For storage solutions such as sync.blue® ADDRESS BOOK, sync.blue® MOBILE Storage, and sync.blue® LDAP, it is preselected by default.

Learn how to merge contacts from multiple sources: How do I merge contacts from multiple sources?

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