Trouble with PMs

[Heather & Angel (GA)]

Sorry to post this off-topic question, but I have some PMs sitting in my outbox that aren't being delivered for some reason. Can anyone explain why?

 

[Randi & Max (GA)]

I believe it is because the person has not read them.

 

[Heather & Angel (GA)]

Oh, I assumed it just worked like normal e-mail.