“This message may not have been sent by…” Gmail Warning Message

If you are getting this warningfrom Gmail saying: “This message may not have been sent by…”, this message is not related to the Wishlist 1-Click Registration plugin in any way.

It is a warning notification from Gmail saying that Gmail could not confirm the email originated from a Gmail sender and that your email is not authenticated.

Please follow Gmail’s guidelines in this link to make sure this warning will not appear again.