Email update:  Cpanel (our hosting software) did an automatic update tonight at approx 8:50pm that we were not notified of & didn’t re-start due to new feature settings they were offering as part of the upgrade.
Email was still going to the server, but was not being sent through to inboxes.  This has since been rectified & emails are flowing as per normal.
If you have any queries regarding this, please let us know.