We are currently experiencing problems with our SMTP mail server. Some users may experience problems authenticating and sending emails through the server.
Incoming email servers are unaffected.
We are investigating the issue and will update when we have more information.
2019-06-10 10:41 UTC: The issue has been resolved and the server is back online, processing out going emails. If you notice any problems, please feel free to open a ticket and let us know.