Along with everything else that took effect on July 1st, Google Chrome began flagging websites that do not have an SSL certificate as "unsecure". HTTPS encryption protects the channel between your browser and the website you're visiting, ensuring no one in the middle can tamper with or see what you're doing. Without that encryption, someone with access to your router or ISP could grab information you send to websites or inject malware into otherwise legitimate pages.
And the scammers are out and in force! If you or your office receives a formal letter about your domain name requiring payment, exercise caution! Scams that come in a formal letter format can give the sender complete control of your domain names if you fill them out and pay for them.
The illustration shows a sample letter, but there are other templates.