Email not sending after update to V 3

After the update to the first V3 version (december 2016) the email reports are no longer sent. After numerous re-installations of piwik and cleaning my hosting site it still doesn’t work.
The install is clean and no plugins exept the Scheduled Task are installed.
Scanned the knowledge base and all tutorials but can’t find out what’s going wrong.

Scheduled Task is not showing the set email reports.

System Check has 2 warnings:

  1. Filesystem:
    My server is using an NFS filesystem.
    This means Piwik will be extremely slow when using file based sessions.
  2. Geolocation (just using the files as the came with the install)