• Start Server Manager
• Go to Features → Add Features
• Select the complete “SNMP Services” subtree
• Click Next → Finish

After installing you'll see an extra service in the services overview.

After installing you can open the properties of the SNMP service in the services overview, but there are no extra tabs yet where you can configure the community strings etc. Before you can configure those you'll have to close all MMC (-related) applications and log off. After logging in the tabs have mysteriously appeared.

Note: My collegue had to reboot the server before the tabs appeared, and on one of the other servers the tabs were just there. No logging off required.

• Agent tab:
  • Set a contact and a location
• Traps tab:
  • Set a community name / community string
• Security tab:
  • Disable the “Send authentication trap” checkbox
  • Configure an accepted community name with the community name you just configured with the permissions “READ ONLY”
  • Set the service to accept SNMP packets from any host

Don't forget to restart the SNMP service.

For ManageEngine monitoring you should allow these ports to go through to your SNMP trap server:

• 135 (UDP)
• 443 (UDP)
• 1025 (UDP5

These ports are not opened by the SNMP service in the Windows Firewall. You'll have to open them manually.