Spamming and Blogspot

I have two blogs, both with Blogspot, and for a while now I've been running the same posts on both of them while I decide which blog to archive and which one to keep (or I might just start over and archive them both).

Anyway . . . I've noticed I've started to get the odd spam message in the comments so I decided to up the security - one blog I have it set so you have to type in the letters and/or numbers to comment, the other the comments are sent to my email and I can decide which ones appear on my blog.

I am appalled at the number of spam comments that I'm getting on old posts! One of my posts from 2010 has 156 spam comments on it. That's just one post on one blog. I know I can go in and delete them all, but I've got hundreds of posts to go through and I'm not sure if it's worth the trouble.

The moderation allows me to prevent the spam from appearing at all, but I can see where having all these comments sent to my email will get old, really fast. The security code, on the other hand, is kind of annoying.

Anyway, my question is this: which do you think is more effective for keeping spammers away, enabling the moderation of comments or enabling the security code?

Well, I found a place in blogger where I can access my entire comments list and got rid of all the spam that made it into my comments without me being aware of it.

I'm finding the comment moderation seems to be the best solution, but I'm surprised that spam I'm still getting is on a handful of posts from 2010 instead of current posts. As long as I don't end up with a flood of spam messages being sent to my inbox, I'm good with being able to pick and choose which comments appear on my blog.