If you're a blogger (or a blog reader), you're painfully familiar with people who try to raise their own websites' search engine rankings by submitting linked blog comments like "Visit my discount pharmaceuticals site." or typical Viagra or Poker stuff. This is called comment spam.

Spam have appeared recently on the blogs hosted by blogexpat. In order to prevent them we have set up several tools options that I remind you below.

• Enable comments

If you untick Enable comments in your blog interface to write new articles, people won't be able to post new comments anymore. Therefore you will avoid spams. This is a very strong method, and instead you may prefer to Moderate the comments, so displaying only comments that you validate before.

• Moderate

When you activate this plugin, comments will no longer appear automatically on the blog when posted. Instead they will be stored for your review in MANAGE/Unmoderated Comments. For each comment you have the possibility to reject it (a spam) or moderate (i.e. validate) and it will be displayed on your blog.

In order to activate this option you must anable the plugin Moderate in CONTROL CENTRE.

• Bayesian Filter

The bayesian filter enable to improve automatic spam filtering. You just need to train the filter by tagging as spams in your dashboard the messages that are spams and the filter will learn to recognise such messages in the future and remove them automatically from your valid comments.

In order to activate this option you must anable the plugin DNS Anti Spam in CONTROL CENTRE.

• Blocked Hosts

In MANAGE/Blog Security you have the possibility to block IP addresses of spammers or people you don't want to post on your blog. Add Blocked Hosts will allow you to block a specific address or entire subnet from your Blog. You can select if you want them to be able to see it, but unable to post or simply unable to access it at all. Copy the offending address into the spaces provided and choose the proper subnet address space if necessary.

Example: To block just the address of 192.168.1.123 you would choose the '32 bits' option to match the entire address. This blocks just this one address and works well for banning someone with a Static IP address.

• Filtered Content

In MANAGE/Blog Security you have the possibility to Add Filtered Content. Anything added here will not be allowed as valid text in a comment in any of the blogs available in this site. Any attempt by a casual user to post a comment with blocked content will block the comment (and display the reason given in the field Reason that you can set yourself).

Regular expressions or a simple string can be used. Regular expressions are much more powerful but they're also much more complex and you should be careful with them, because you could potentially block all content with the wrong regular expression.

• NoFollow

A lot of spammers try to raise their Google rank (the way they try to reach to top page on Google search for some queries). From now on, when Google, Yahoo! or MSNSearch see the attribute (rel="nofollow" on hyperlinks, those links won't get any credit when we rank websites in search results. This isn't a negative vote for the site where the comment was posted; it's just a way to make sure that spammers get no benefit from abusing public areas like blog comments, trackbacks, and referrer lists.

Therefore by flagging the option No Follow you will remove the attract of your blog for spammers.

In order to activate this option you must anable the plugin NoFollow in CONTROL CENTRE.

We are always trying to add new methods to avoid spams on blogexpat. In the future you might see options such as image validation or specific question before to post comments, thus making life for spammers more difficult.