Sole mail rule for that domain says "forward *@mydomain.com to mygmailaccount@gmail.com".

Mail sent from myyahooaccount@yahoo.com to anyone@mydomain.com arrives in mygmailaccount@gmail.com's inbox, marked unread (expected behaviour).

Mail sent from mygmailaccount@gmail.com to anyone@mydomain.com is sent, but I get no bounce, and no message back in. It sits in the Sent section.

Mail sent from mygmailaccount@gmail.com to mygmailaccount@gmail.com is sent, but as well as sitting in the Sent section, appears in the inbox marked unread.

In each case there is only one instance of the message.

So the question is: why does the gmail account mark mail sent to itself unread and put it in the inbox, but bypass the inbox completely if it goes via an unrelated domain with a forwarding rule?

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