I had two identical emails and the first appeared as a contact request (or maybe the second) and blocking would not make it go away. So in the end I had to delete it.
The only other thing that might be unusual, apart from there being two consecutive identical emails, is that the “to” address was different from the “delivered to” address.
Strange… Do you still have the original email in the web client? (the web client is where you probably usually read your emails)
If yes, can you send us the source of the email? There should be some button like “view source”, “view original message”, “view full email” or sth. like this.
I still have the messages. They are on the IMAP server. I marked them as unread using Seamonkey, and then I went into delta chat and unblocked the sender, then quit delta chat and restarted it, but I cannot see them now as contact requests. Maybe I have to wait a while? I don’t want to post the emails to the forum as they have my email addresses in them.