clean email addresses?

Does anyone have suggestions for cleaning a list of email addresses?


       I ask, because I can read into R data on registered voters that 
includes an "email address" field.  I wondered if anyone had experience 
doing such, especially in R.  (I found an article on "How to Clean Large 
Email Contact Lists for Email Marketing Campaigns"; 
"www.wikihow.com/Clean-Large-Email-Contact-Lists-for-Email-Marketing-Campaigns". 
Before I went further with this, I felt a need to ask.


       Thanks,
       Spencer Graves