public ChannelPipeline getPipeline() throws Exception {
ChannelPipeline pipeline = pipeline();
pipeline.addLast(GROUP_HANDLER, groupHandler);
pipeline.addLast("idleHandler", new IdleStateHandler(timer, 0, 0, timeout, TIMEOUT_UNIT));
pipeline.addLast(TIMEOUT_HANDLER, new ImapIdleStateHandler());
pipeline.addLast(CONNECTION_LIMIT_HANDLER, new ConnectionLimitUpstreamHandler(IMAPServer.this.connectionLimit));
pipeline.addLast(CONNECTION_LIMIT_PER_IP_HANDLER, new ConnectionPerIpLimitUpstreamHandler(IMAPServer.this.connPerIP));
// Add the text line decoder which limit the max line length,
// don't strip the delimiter and use CRLF as delimiter