Email alerts missing (compared to event log)

[BillP]

Hi all

I have a UPS here, that is configured to send email alerts on power fail (with no delays).

I see short power fail events in the event log (less than 30 sec), and corresponding power recovered messages.

The email alerts however, do not match.  They are not always sent.

Some examples

02/09/2018	04:20:21	Device	UPS: No longer on battery power.
02/09/2018	04:20:15	Device	UPS: On battery power in response to an input power problem.
02/09/2018	04:05:42	Device	UPS: No longer on battery power.
02/09/2018	04:05:27	Device	UPS: On battery power in response to an input power problem.

Neither of these generated an email.

The following event Did generate email alerts - one for each event as expected.

03/29/2018	04:42:50	Device	UPS: No longer on battery power.
03/29/2018	04:42:35	Device	UPS: On battery power in response to an input power problem.

Email alerts for other events are working before the above issue, and again after.  So its not an email issue. (I would see this I think as a mail delivery failure in the event log anyway)

I dont believe the alert mail config (delay parameter) has changed in this time.  There are no events listed to indicate config changes.

Any ideas ?

(Its not limited to power fail events either)