[logback-user] Logback with Postfix

I'm trying to set up logback for use with Postfix running locally on the same machine as my app. I am using the following: <appender name="EMAIL" class="ch.qos.logback.classic.net.SMTPAppender"> <SMTPHost>localhost</SMTPHost> <To>brian.moschel@gmail.com</To> <From>brian.moschel@gmail.com</From> <Subject>TESTING: %logger{20} - %m</Subject> <layout class="ch.qos.logback.classic.html.HTMLLayout"/> </appender> This does not work though. It hangs forever and my local mail logs never receive a request. The local mail server is running at port 25. I can run "mail <some email address> to sucessfully mail someone on this machine. Any ideas how to debug this? Thanks, Brian