I have received the email below several times over the past few months. I believe is is a phishing email because my account is not past due. I want everyone to be aware of this "official-looking" email.
Have you checked with the Website Builder integration's support to see if that email is actually spam? You do have a published site and unique domain, so it's entirely possible this is a legitimate notification from them.
If you need resources and ways to connect with the WSB integration's support, make sure to check out their Knowledge Base site (also available via the Website & Stores tab of your account).
If it is indeed a phishing email, please forward it to reportphishing(at)constantcontact(dot)com so our Compliance teams can further investigate it.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ William A Community & Social Media Support