Question about "read" messages

[flagg07]

Are you Gents able to determine if a trader actually reads their PMs?

As a sender, a message goes to the outbox when it's sent and to the sent box when it's read.

As a receiver, I get a prompt showing how many new messages I've got. After I open the 1st message, the prompt will show zero new messages, but the other 2 messages will be highlighted in red showing me that they have not been read. What happens on the other end?

I'll use an example to clarify my question:

Trader A posts an ad and gets PMs from Traders B-F.
Trader A logs in and sees 5 new messages while Traders B-F are showing 1 message each in their out box.

Trader A reads Trader B's message. Trader B's message goes to his sent box. Trader A's prompt shows 0 new messages, but the unread messages are still highlighted in his inbox.

What do Trader C-F see? Do their messages remain in their outbox?
Does Trader A's reading 1 message move only that message or does it move all of them?

These probably sound like silly questions... I'm asking them due to the considerable amount of "lost communication" I've encountered in the pasty few months. I'm less inclined to post in the back out threads if there's even a remote possibility that the messages in my sent box are not actually read on the other end.

I'm confident that only the read message should move for that sender, but I'd like to confirm that's how it actually works.

[HarlequinZero]

Until that red icon indicating an unread message goes away they will remain in the outbox. In other words, the recipient really does have to read it. However, the only exception is if the PM targets multiple people. In that case as long as one of the recipients reads the message it will move to the sent box.

[flagg07]

Thanks.