See www.zabbix.com for the official Zabbix site.
Status: Initial draft, do not comment
It is not possible to send any alerts on acknowledgement of a trigger. This functionality is really important and should be supported by Zabbix.
Configuration of trigger actions
New fields in tab 'Action' placed after existing 'Default message'
Acknowledgement subject [ ] # input box, same as for 'Default subject' Acknowledgement message [ ] # text area, same as for 'Default message'
New options for operation placed after 'Operation type' only if 'Send message' selected
Send: <Message>/<Message + all acknowledgements>/<Message + 1st acknowledgement only>/<All acknowledgements only>/<1st acknowledgement only> # drop-down Send acknowledgements till step: 
A new Zabbix server process will process new acknowledgements and generate new events.
Source: EVENT_SOURCE_TRIGGERS Object: EVENT_OBJECT_ACKNOWLEDGE Object ID: acknowledge ID Value: 0 - first acknowledgement, 1 - for all following acknowledgements
New or updated string
- What's new in 2.4
To be discussed
- How does maintenance affects this functionality?