Some clients experience a Server Maintenance issue this morning or are unable to send test emails. We are addressing the problem. We'll keep you posted here.
Update: Server is now stabilized. Everything is working correctly. If you encounter any problem, please report them here. We will be investigating what happen and make sure the safeguards are in place to avoid that in the future.
Update #2: Some clients still have problem sending test emails. We are investigating.
Update #3: Problem with test emails are now fixed too. Let us know if you encounter any other problem.