Spam block prevents a faulty Event Rule to send to many emails or SMS messages to one single recipient.
A typical scenario you want to avoid is that larger email providers like GMail, Yahoo, and Hotmail will block your email server if you start to send hundreds of emails to one address during a shorter period of time.
Another scenario to be careful with is sending a larger number of SMS, which is both annoying and expensive.
Under SiteAdmin > Settings > Email you can set the number of emails per 60 minutes that are allowed to be sent to one email address. The default is 30. If more than 30 email notifications are sent, no more emails are sent for one hour. GpsGate will also send a notification to the SiteAdmin's email address with information.
Under SiteAdmin > Settings > SMS you can set the number of SMS per 60 minutes that are allowed to be sent to one phone number. The default is 10. If more than 10 SMS messages are sent, no more SMS messages are sent for one hour. GpsGate will also send a notification to the SiteAdmin's email address with information.
How to fix the problem
In the spam block notification email you will also see which email address or phone number is temporarily blocked. You can search for it in the Terminal under SiteAdmin > System Tools to find out which username and application it belongs to.
Under SiteAdmin > System Tools > Profiler > CommandNotifier you can see which event rule in which application is causing all SMS/emails to be sent. Login to the application and disable the event rule, or change it to generate fewer notifications.