due to changes in PHP-MAPI which will be available with the next KC 8.5 release and are already available as nightly builds we’re relasing an updated Z-Push 2.3.8 which reflects these changes. The changes are backwards compatible with earlier KC versions. If you are running KC 8.4.90, you have to update Z-Push to this version. If you are running an earlier KC version, the update is not necessary. It will be available in the next regular Z-Push release.
The updated version is available in repositories (how-to install Z-Push 2.3.8 from the final repositories (recommended): https://wiki.z-hub.io/display/ZP/Installation) and a tarball (not recommended): http://download.z-push.org/final/2.3/z-push-2.3.8.tar.gz