There seems to be a problem in the way Zabbix server handles ACTIONS. I have a script which sends me a SMS message each time there is a problem. The script is ran by a Zabbix action. Below is an example:
I have 2 triggers:
A = "Service SMTP 25"
B = "Exim not running on host smtp.example.tld"

A is dependent on B. Both triggers are active because process exim is not running on smtp.example.tld but trigger A is not shown in Zabbix frontend because B is active and A depends on B. Strangely I don't get any action SMS notification about trigger B but I get notifications about trigger A.