Back links are important for any website for better search results ranking.Some of the most common strategies implemented by bloggers is allowing do-follow on the comments made by visitor, which can be used to get back links from higher Page Ranked blogs.This technique also has a drawback, with the intention of taking advantage of the do-follow status, the comments section could be flooded with spam email.To have better control over spam comments from taking advantage of the system, you can implement stringent comment and do-follow rules using WP Manual Do-Follow Plugin.
This plugins lets the administrator set the number of comments required by a visitor from a unique email address to automatically have DoFollow status.Administrator can also manually override the rel=follow status on a blog.The Do-Follow status can be set to either Author Link or Links in the comment or both. 
Manually moderating each comments can be hard, so the process can be automated by enabling “Automatism” which enables ‘ DoFollow ‘ Status to comments by all users with more then X comments automatically.
Broken links can also be bad for SERP Ranking.This plugin has a URL Validation feature to check all DoFollow Link from time to time if the URL is reachable.It its not reachable it intimates the admin by email.
Also Read :
How To Install and Use SMu Do Follow WordPress Plugin :
- Download, Install and Activate the plugin
- A new entry of SMu Do Follow is available from where the plugin can be configured further.
If you plan to make links on your blog a DoFollow then try this plugin to moderate links for better control.Do Share your thoughts about the plugin.
Nice post. Thanks for this post. I has made the use of do-follow plug-in, it is very useful and even every one can get benefit of these plug-in.