Try to use "paste snippets" feature in QtCreator
Tools -> Code Pasting -> Paste Snippet...
1.) Select Paste.KDE.ORG as Protocol and try to post something. When clicking on the Paste" button creator prints
Paste.KDE.Org protocol error: Could not send entry.
Result: Nothing is posted
2.) If you try to use pastebin.Ca as Protocol you get the following message:
Pastebin.Ca protocol error: Error downloading http://pastebin.ca/quiet-paste.php - server replied: Internal Server Error
Result: the message is posted but no URL is printed to QtCreator's "General Message" tab telling me under what URL it was posted.