This Google search result explains what Akismet is:-
If you click on this link, you will be taken to an article, part of which is a section headed, “How to install and configure Akismet.” Although we are yet to check it out fully, our first impressions are that it’s one of the best guides as to how to carry out a technology task we’ve ever come across. Amongst other things it has lots of screens shots of what it’s talking about – something that is missing in most such guides. It’s perfect for what we are always talking about – printing it out and following it’s instructions step by step.
As we’ve often said, “We have a dream,” and that dream is for a world in which, whenever we want to carry out a technology task, there’s a guide like this one to help us – a world which we think is a million miles away at present.
A 19 May 2018 update: Of course, if the person or organisation you want to deal with has an ordinary email address, and and when you use it to send letters and you get good replies, you seldom need guides like the ones described above. This seems to be the case with Akismet. We have very limited experience with them – but they have an ordinary email address – firstname.lastname@example.org – and when we have used it to send them 2 letters we have got 2 more than satisfactory replies.
We would be interested in what experiences any of our readers have had with them.