Sending a message is one of the best ways of notifying people about a problem. That is why it is one of the primary actions offered by Zabbix.
To be able to send and receive notifications from Zabbix you have to:
Zabbix sends notifications only to those users that have at least 'read' permissions to the host that generated the event. At least one host of a trigger expression must be accessible.
You can configure custom scenarios for sending messages using escalations.
To successfully receive and read e-mails from Zabbix, e-mail servers/clients must support standard 'SMTP/MIME e-mail' format since Zabbix sends UTF-8 data (If the subject contains ASCII characters only, it is not UTF-8 encoded.). The subject and the body of the message are base64-encoded to follow 'SMTP/MIME e-mail' format standard.
Message limit after all macros expansion is the same as message limit for Remote commands.
You can view the status of messages sent in Monitoring → Problems.
In the Actions column you can see summarized information about actions taken. In there green numbers represent messages sent, red ones - failed messages. In progress indicates that an action is initiated. Failed informs that no action has executed successfully.
If you click on the event time to view event details, you will also see the Message actions block containing details of messages sent (or not sent) due to the event.
In Reports → Action log you will see details of all actions taken for those events that have an action configured.