[Plugin: Contact Form 7] Receiving mail as junk

Hi Takayuki
The mail arrives to the junk mail folder, when it’s there a small flag (with a red cross) says “Smart Screen Filter has detected this mail as spam, it will be deleted in ten days”.
I select the message and select “Not junk”, then the message is in my inbox but the same red cross now says “This message didn’t pass the smart screen filter”, but..well it’s there.

If I send THE SAME MESSAGE with the SAME SENDER the scenario repeats itself: firts to junk and then to inbox (after I whitelisted it), but alwasy the red cross with the message.

Thing is, Im not the one managing the messages sent by contact form 7, the one person that does it, well, he’s not very good at computers (but great at PR), and he’s asking me for “a solution”, I guess it will be to receive the mails not flagged in his regular inbox.

Thanks for your time.

EDIT: The messages go to the spam folder of gmail also, but without any kind of alerts.

EDIT 2: I updated to your 2.3.1 version and selected “Use HTML content type”. The messages arrive to the (normal) inbox BUT with a warning: “This message looks suspicious to our SmartScreen filters.”
I can live with it, unless you tell me if there’s something to “fix” it.