Disassemble your plugin. Search for the string SendEQMessage in the disassembly. If it's there, and you're using a recent compile from this site or the latest source from MQ2, then your plugin will probably try to send packets, but be unable to. Next, search for the string send_message. If that one exists, then your plugin can send packets and is probably unsafe. I hear most of the plugins people buy are encrypted or have odd obfuscation done on them so this test might not work for you.