The libc-client package provides a software API for accessing mailboxes.
Due to segmentation fault issues with large (4096 bytes) mail headers and Kolab patch maintenance, a more recent version of libc-client is used. The version matches the one found in ClearOS 6.x.
This patch is required for the Kolab free/busy system. It is hoped that this patch will be included in a future upstream release. You can get more information on this patch from the Kolab Patch web page.