Pass..:wacko:
The process is as follows:
1: Person sends PM.
2: System places message in senders "outbox".
3: System sends email notification to recipient that a PM is waiting
4: System sets PM waiting status for recipient, so when the user logs in, they get the message saying message waiting
5: recipient logs in, message is moved from outbox of sender to inbox of recipient.
Between stages 4 and 5, the sender can delete this message out of their "outbox". Either intentionally or unintentionally.
If it is deleted, it will not appear in the recipients inbox, but the recipient will get all the messages saying that they have a PM.
This has happened before, as people are sometimes "too tidy". They delete messages from their outbox, thinking they are saving space, but actually, those messages are not wasting space, they are just waiting to be delivered.
Once the message is delivered, it is automatically removed from the senders outbox.
It may be that the person that sent you the message, has just been "too tidy", and deleted the message before you logged in.
As it has been deleted, there will be no way of knowing who sent it, or when. Hopefully they may read this and send it again.
Hope that helps everyone understand how the PM system works.