How do I delete an unsent offline request for read receipt?

[Martin]

Someone has sent me a message with a read receipt request. The associated
account is a receive only account and therefore this read receipt is stuck in
'sending' and repeatedly tries to send the receipt when I connect to the
internet. How do I delete this receipt?

 

[Mike]

Martin:

Did you ever get an answer to this post? I am having the same problem