Noun
appender (plural appenders)
(computing) A software component that appends data to a computer file.
Log4j also includes a socket-based appender similar to the one I illustrate in this article. Source: Internet
You could even write appenders to send people pages or SMS (short message service) messages when something goes really wrong with the system (though the built-in SMTP appender might be able to do that as well). Source: Internet