Email Subscriptions Not working Please act immediately

Perhaps a coincidence however I'm experiencing the same thing.

I'm the admin for several workspaces, datasets and dashboards/reports. All our datasets refresh at around 8 am and email subscriptions (12 in total) usually arrive around the same time. For the last few days these have been significantly delayed (.e.g. I've just received (at 13:01) an email for a dashboard that refreshed at 8 am this morning.

Perhaps this is a wider issue?