Summary and Impact to Customers
On Thursday 5 th September from 07:48am – 09:52am, SYNAQ Securemail experienced a service
incident which affected the delivery of mails for all .za domains.
The resultant impact of the event was that Clients were unable to send and receive mail to and
from .za domains.
Root Cause and Solution
The root cause of this event was due to an issue experienced by the ZA root servers where they
were no longer allowing secure queries from DNS servers. As a result, when our DNS cache servers
were trying to query the affected root servers, it was returning an invalid response, which resulted
in the inability to send and receive mails to and from .za domains.
In order to resolve this issue, the enforced secure queries capability were disabled to the ZA root
servers and we were once again able to resolve all .za domain information.
Custom monitoring checks are going to be built to proactively identify these forms of DNS