Message Missing From Sent Items?

Hey all,

I am curious how exactly the messaging works on Plenty of Fish. I sent a message to someone and it was in my sent messages section of my inbox. Fine. I go back an hour later and see that the message is gone from my sent box. I have no incoming messages from this person, nor do I have the outgoing message.

I assumed I was blocked, but when I went back to my search, this person was still listed in the search. I clicked "Send Message" and it took me back to my message that I previously sent them. So the message DOES exist!

My question is: what happened here? Did they delete my message without responding? Am I blocked even though I can still see their profile? Or did POF reject my message for some reason?

Thanks in advance!