I just read the man crond . It says that it uses the mail program. I tested the mail program from the shell and it works.
Is there a way to debug what happens to the task cron output when crond runs a task from the crontab?
Regarding upgrades we do them after we test programs that we need in the development environment before we upgrade them in the server. So we will upgrade to a more recent OpenSuSE version after we finish the tests of those programs in the the development environment.