The newGeneral Data Protection Regulation of the EU comes with a few things we'll have to watch out for and will be implemented on the 25 May 2018.
A short liste of the things to look out for, can be found HERE (German)
Since we aren't allowed to send personal data to all student but the one it is intended for, you should not send all the points/marks to all students. Each student must only get his test result and not be able to get insight into the results of his colleagues. In the E-Mail HowTo you can find a workaround to create serial-E-mails which do just that.