I keep getting spam that goes something like this:

We noticed that you are not at the top of the search engines for a number of
your key terms. We have helped companies similar to yours to achieve top
organic rankings. Please reply to this message and we will prepare a special
proposal for you, to show you how we can achieve similar results for you.

Given that they daren’t leave a URL, don’t use a real name and spam you via address forms, … would you trust them to do a decent job? No, I think not.