You would send a message to another member from their ad or profile page. When you do, the other party is sent an email notification about it with a link to your ad or profile. Your message is also recorded on your Messages page in your Mindahome control panel. When they reply you will be notified and you will need to respond to them from your Messages page. You can see if they have read your message under the date and time it was sent. There is more information on your 'How to' page also found in your Mindahome control panel.