With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fgApPOP3MemUsage
fg Ap POP3 Memory Usage
1.3.6.1.4.1.12356.101.10.102.2
Memory usage of the POP3 Proxy (percentage of system total)
Back to FORTINET-FORTIGATE-MIB MIB page.
IPHost Network monitor allows you to monitor fgApPOP3MemUsage on Fortinet device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Fortinet access points right now.