I have enabled the "Report not supported items" internal action so that I can receive notifications when an item becomes unsupported.
The problem I am having is that occasionally an item will become unsupported momentarily (because of connectivity issues for example), but 30 seconds later will become supported. This results in many redundant problem and the ok alert emails.
I know how to make alerts based on triggers less sensitive, but how do I do that with internal items? Note that I am comfortable with the fact that the item becomes unsupported momentarily.
You might wish to configure escalations in such a way that the email is not sent immediately, but on a second step, for instance. This way, only if the item is still unsupported when the second escalation step is executed, will the email be sent.
Please see https://www.zabbix.com/wiki/doku.php?id=howto/config/alerts/delaying_notifications for more information.