Lots of bloggers have major spam problems. (Can you relate?) I used to be one of them, having gotten 55 spam comments just overnight in one instance. I had blocked 121 unique spammers from commenting and still they kept coming in. However, I have not received one spam comment on this site since I discovered the now-obvious solution to all spam problems on a WordPress site. This may not work for everyone, such as those with very large WordPress sites, but by turning on the ‘Users must be registered and logged in to comment’ feature. Why is this so effective? Because many spammers are not actually WordPress users; rather, they simply use their email (this is not even always required either) to comment on your site.
The only downfall of doing this (this applies to blogs with a very large amount of readers) is that many can no longer comment on your site because they, too rely on this ability to comment without being logged in.
So, depending on your situation, you just might be able to rid your blog of spam without the help of Akismet. Thank you for reading, and I hope this helps you!