private void onServerLoop() {
		acquireConnectionPermit();

		acceptServerSocket(this.serverSocket)
				.flatMap(this::establishSocketSession)
				.map(this::addSessionsSynchronizedToActiveList)
				.ifPresent(this::executeSocketSession);
	}
Accept connections and run them in session threads until shutdown.
src/main/java/de/gessnerfl/fakesmtp/smtp/server/BaseSmtpServerRunnable.java