'My Messages' -> on the left site click 'Search Messages' (
click here for direct link) -> enter the username into the field 'by user' -> click on search -> profit
Thank you but I didn't get what I'm looking for.
If I follow your suggestion, system asks me to put a query(part of a message), but it doesn't execute the conversation. I'm looking for the total conversation with a certain user, for ex. bob123
Edit
If I put a query and check the box "Show full message in results", I get all the message from a certain user.
Thank you.
But it would be better to have the total conversation.