private SocketSession addSessionsSynchronizedToActiveList(SocketSession socketSession) {
		// add thread before starting it,
		// because it will check the count of sessions
		synchronized (this) {
			this.sessionThreads.add(socketSession.session);
		}
		return socketSession;
	}
Accept connections and run them in session threads until shutdown.
src/main/java/de/gessnerfl/fakesmtp/smtp/server/BaseSmtpServerRunnable.java