Is semalt.expert Safe?

Have received a dozen or so spam emails from ***** today, the emails are branded as from Full-Stack Digital Agency though all URLs point to ***** They seem to be just sending out emails based on Whois data - the email address used is not public and several of the domains are not in use. The spam reads.... "We have checked Google rankings of the following website: >Domain Name< And we have found 14 errors that negatively affect your website's growth in Google, your client flow and sales. We provide business owners, webmasters, analysts and marketing experts with new ways to effectively use web tools for any kind of business by offering high-quality SEO promotion, web development, explainer video creation and advanced analytics services. " Odd that every site had the same number of errors too :)