eMule requires open ports to function. If your router blocks port 4662 (TCP) and 4672 (UDP), you may connect to servers, but you will have a Low ID. Go to Options > Connection > Test Ports .
: Import an ipfilter.dat to block known bad actors. Download emule server.met
The file is essentially a phonebook. It is a plain text (or structured data) file that contains a list of all known eD2k servers, including: eMule requires open ports to function
To keep your server.met fresh without manual work: you may connect to servers