As a result of some changes we made to our network (following the DDoS attacks) we are seeing some outgoing delivery delays to certain email providers. Most notably these are Yahoo, Outlook and Microsoft 365/Office 365.
It appears that because our outgoing mail server now has a different IP address they are deferring delivery of messages for the time being.
This is extremely frustrating and we are seeing long delivery delays. We are working to resolve this issue as quickly as we can and will include updates on the situation here.
Update: 26-Oct-2021 23:57 CEST – We have made some further changes to the outgoing delivery servers and the mail queue is currently dropping quickly. We will monitor the situation for the next couple of days. Sorry for the inconvenience caused.