Проблема с log4j

import org.apache.log4j.Logger;

public class Loggers {
    static Logger logger = Logger.getLogger(Loggers.class);

    public static void main(String[] args) {
        logger.error("Hello");
    }
}

log4j.rootLogger= ERROR,gmail
log4j.appender.gmail=org.apache.log4j.net.SMTPAppender
log4j.appender.gmail.SMTPProtocol=smtps
[email protected]
log4j.appender.gmail.SMTPPassword=111111
log4j.appender.gmail.threshold=error
log4j.appender.gmail.SMTPHost=smtp.gmail.com
log4j.appender.gmail.SMTPPort=465
log4j.appender.gmail.smtp.starttls.enable=true
log4j.appender.gmail.Subject=Logging Message via Gmail
[email protected]
[email protected]
log4j.appender.gmail.layout=org.apache.log4j.PatternLayout
log4j.appender.gmail.layout.ConversionPattern=%d{MM/dd/yyyy HH:mm:ss}[%M] %-5p %C - %m%n 
log4j.appender.gmail.BufferSize=5

Ошибка

log4j:WARN No appenders could be found for logger (Loggers). log4j:WARN Please initialize the log4j system properly. log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.