Method _connect

app/src/main/java/eu/faircode/email/EmailService.java:871–980

(
            InetAddress address, int port, boolean require_id, String user,
            SSLSocketFactoryService factory)

    }

    private void _connect(
            InetAddress address, int port, boolean require_id, String user,
            SSLSocketFactoryService factory) throws MessagingException {
        EntityLog.log(context, EntityLog.Type.Network, "Connecting to " + address + ":" + port);

        isession = Session.getInstance(properties, authenticator);

        breadcrumbs = new RingBuffer<>(BREADCRUMBS_SIZE);

        boolean trace = (debug || log);

        isession.setDebug(trace);
        if (trace)
            isession.setDebugOut(new PrintStream(new OutputStream() {
                private ByteArrayOutputStream bos = new ByteArrayOutputStream();

                @Override
                public void write(int b) {
                    try {
                        if (((char) b) == '\n') {
                            String line = bos.toString();
                            if (log)
                                if (line.endsWith("ignoring socket timeout"))
                                    Log.d("javamail", user + " " + line);
                                else
                                    Log.w("javamail", user + " " + line);
                            bos.reset();
                        } else
                            bos.write(b);
                    } catch (Throwable ex) {
                        Log.e(ex);
                    }
                }
            }, true));

        //System.setProperty("mail.socket.debug", Boolean.toString(debug));
        isession.addProvider(new GmailSSLProvider());

        if ("pop3".equals(protocol) || "pop3s".equals(protocol)) {
            iservice = isession.getStore(protocol);
            iservice.connect(address.getHostAddress(), port, user, null);

        } else if ("imap".equals(protocol) || "imaps".equals(protocol) || "gimaps".equals(protocol)) {
            iservice = isession.getStore(protocol);
            if (listener != null)
                ((IMAPStore) iservice).addStoreListener(listener);
            iservice.connect(address.getHostAddress(), port, user, null);

            // https://www.ietf.org/rfc/rfc2971.txt
            IMAPStore istore = (IMAPStore) getStore();
            if (istore.hasCapability("ID"))
                try {
                    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
                    boolean client_id = prefs.getBoolean("client_id", true);
                    Map<String, String> sid = istore.id(client_id ? getId(context) : null);
                    if (sid != null) {
                        Map<String, String> crumb = new HashMap<>();
                        for (String key : sid.keySet()) {