Here you will find answers to your questions. The FAQs refer to all our products and related processes. If you cannot find what you are looking for, please, ask our e-mail support for assistance. Please, select the proper product needing our support:

How do I resolve NDR (Non-Delivery Report) problems?Show more

If you have NDRs then Outlook / Exchange cannot bind a LEGACYEXCHANGEDN to a contact.

Please read the blog article THE ATTRIBUTE, THE MYTH, THE LEGACYEXCHANGEDN by Michel de Rooij to get general information about the legacyExchangeDN attribute:

The first solution is to reconstruct the old LEGACYEXCHANGEDN and to save it as X500 address in the PROXYADDRESSES attribute of the contact.

For Example:
You want to send an email to Ron Smith and receive the following NDR:
IMCEAEX-_O=TEST_OU=First+20administrative+20Group_cn=Recipients_cn=Ron.Smith #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##

Then the X500 address within the PROXYADDRESSES should be:
X500:/O=TEST/OU=First administrative Group/cn=Recipients/cn=Ron.Smith

The LEGACYEXCHANGEDN must be unambigious within an Exchange forest. During the check, all LEGACYEXCHANGEDNS and X500 addresses must be checked.

The second solution is clearing the NK2-Cache, this must be done for all affected uses.
For more information read:



19031 (15770) Not all mails arrived ...Show more

In this case the sender sent his data file splitted into multiple mails. The error indicates that GALsync on the receiving side tries to contact Exchange Online before all sent objects are really present in Exchange Online - even if you can see the mail within your OWA App.

Wait up to 5 minutes between receiving the data and running the import policy.

11021 (15838) - LegacyExchangeDN of the GALsync service account is in the old syntax.Show more

Please update this by re-mailenabling the service account or create a new GALsync service account.

Your current GALsync service account is migrated from an Exchange 2003 environment. The LEGACYEXCHANGEDN of the GALsync service account is in the old syntax, which was used up to Exchange 2003, however GALsync 5 need a service account with a mailbox which has the new LEGACYEXCHANGEDN syntax which is used by Exchange 2007 and higher.

Please create a new GALsync service account with a new mailbox and the same permissions like the old one.
After that log on with the new GALsync service account, run the GALsync GUI with the new GALsync service account and change the GALsync service to the new GALsync service account.
Use CONFIGURE SERVICE to start the wizard for changing the service account of the GALsync service.

28104 - Error adding value of property showInAddressBook to the contactShow more

If you use the CUSTOM SETTINGS at the ADDRESS LISTS tab of Import Setting, you have selected an address list, which isn´t available anymore in your environment. 





Please check the CUSTOM SETTINGS of the ADDRESS LISTS tab of the Import Setting and save the import policy again, so that the wrong entry is removed. Otherwise use the DEFAULT SETTINGS.

What to do when I notice an error / bug?Show more

We always try to provide a very responsive, solution orientated and effective support. Should you encounter any issue, bug or inconvenience please do not hesitate to contact us via

To enable us providing you the best quality support, please provide us with the following information:

  • Environment Overview
    • GALsync Installations (Planned and Implemented)
      • Domain Infrastructure (e.g.: Single Domain “dom.local”)
      • Exchange Version (e.g.: Exchange 2010 SP2)
      • Windows Version of GALsync Machine (e.g.: Windows Server 2008 R2)
      • GALsync Version (e.g.: 6.0.x)
      • Does the GALsync Service Account have an Exchange Mailbox?
      • Did you log on to the GALsync Machine using that Service Account to configure the policies?
      • Is the GALsyncService logging on using the Service Account?
  • Please describe your issue/bug/inconvenience thoroughly, in detail, what you wanted to achieve and what you were doing as it occurred.
  • A screenshot of the issue often helps us to understand
  • We also require the configuration and the logs, preferably zipped.

    In menu Action -> Export Configuration you can zip the policies.
    In menu Action -> Export Status you can zip the log files.