# Miscellaneous - Knowledge Base

## 1. What is Community?

Community refers to the SNMP Community string of the device. For most of the devices, the default community string is "public".

You can use the SNMP Tools --> Community Checker tool to get the community string of the device. It has a list of default community strings of various devices, which queries to find the matching community string of the device.

Please ensure that the queried device is SNMP enabled.

[Questions](https://www.manageengine.com/products/oputils/knowledge-base.html#miscellaneous)

## 2. How to install/enable SNMP?

To install or enable SNMP in Windows or Linux OS, refer to the online [help documentation](https://www.manageengine.com/products/oputils/help/snmpinstallation/snmp_installation_intro.html)

[Questions](https://www.manageengine.com/products/oputils/knowledge-base.html#miscellaneous)

## 3. When I use the Send Email option, I get an error: "E6002 : Unable to send mail".

The possible reasons could be:

1. You have not configured the SMTP settings. Select Admin --> Settings --> SMTP tab and configure your mail server and save.
2. Any security software like Mcafee or Symantec running in the m/c running OpUtils is blocking this. Check after stopping it.

[Questions](https://www.manageengine.com/products/oputils/knowledge-base.html#miscellaneous)