Email reports not sent since 2.0 on OVH (no replies)

Hi,

Since I upgraded to Piwik 2.0, my email reports are never sent (although they should be sent everyday).
I now run 2.3, and this is still the same issue.
Note that:
- I installed Piwik on a shared hosting server (OVH)
- sending instantaneously a report works fine
So this looks more than a scheduling problem than email problem.

What could I do?

Thank you