I've received an email from an 'Online Strategist', is it legit?

The email content goes something like this:

"Hi, My name is Olivia and I am an Online Strategist. I've been tracking the success of your website while doing some research on your industry—I'm impressed with your company, but there are some real opportunities for growth that you currently are missing. Are you interested in several proven strategies to use content and social media to drive relevant traffic to your site? In 20 minutes I can show you how to fuel your brand and generate more revenue from search engines and social networks. This is a $500 value free of charge. I’d like to follow up about this with a quick phone call. Can I call you this week to discuss your campaign? Thank you Best regards, Olivia"

and another one:

"Hey Guys, I hope you're well. My name is Ryan I work for a local online marketing company in Melbourne. I was doing some research on some of your competitors when I came across your site. I noticed while you have a decent looking website, you don’t appear in Google’s organic listings for a whole bunch of keywords pertaining to your industry. The agency I work for could get you guys a lot more leads online. Whether that is through making sure you appear in the organic listing (where over 80% of people click) on Google, or Just by making sure your website convert a lot more visitors into leads. Given your current landing page, I can only assume it's not converting anymore than 3% of people visiting your site. I hope you don't mind me emailing, I just find it a little less invasive from calling you up and interrupting what ever it is you are doing at this present moment :) If this sounds like something of interest, or something you would like to explore further - simply reply with full contact details and I will give you a quick buzz. Regards, Ryan"

I received the above emails myself and have seen many variations claiming my website supposedly does not comply with Google or does not rank well.

Funny thing is, all of the emails I have checked from these spammers have a similar theme:

• their own website (or company name, contact details...) are missing from their email signature (not so great online strategy!)
• upon looking at their domain, they don't even seem to have a website at all (how can this be taken seriously?!)
• some of their emails come from gmail account or similar (even less professional)
• how would they know what my desired key words are, what I'm trying to achieve or if I need more leads
• If they researched my website as they claim, how would they know I'm missing opportunities when I've had great results from my website over the past 10 years?

Although these emails sometimes sound convincing especially if they are based in Australia, these messages are aimed at most business owners who don't have time to research the web. I've done the research for you and rest assured these emails are nothing but spam, they have not researched your website in particular, this is a mass mail-out. To any of our clients, please let us know if you have any queries or ever receive a similar email that you are unsure of. We're happy to check it out for you!