Update 16:20 CET: service is now fully restored. An investigation and root cause analysis will follow in due course.
Update 16:00 CET: we have implemented workarounds for a number of affected sites. Please contact firstname.lastname@example.org if you are still experiencing connection errors.
As of 15:30 CET we are investigating a partial outage at our Amsterdam 1 datacenter. Updates to follow as soon as we know more.