End Google Ads 201810 - BS.net 01 --> I have MFC-based SDI GUI application.

Also I have a thread which contains custom messages queue. Each of these messages should be posted to GUI, most of them adds new items to ListView.

If I'm just doing PostMessage( WM_MY_CUSTOM_MESSAGE ) to main GUI thread I have 2 undesirable effects:
1. Main thread queue is overflowed and I have message-leaking;
2. GUI becomes unresponsible - windows aren't repainted, I can't push toolbar and dialog buttons and so on;

Question:
How can I organize posting messages to GUI from the secondary thread and avoid 2 above effects (especially the second one)?