Using electronic messaging systems for the unwanted messages in bulk quantity is called spamming. And the Person doing this form of work or engaged in this form of work is called. In other word mailing to the persons who does not like to receive your mail is called spamming.
Now come to the point why I write the "Make Sure You Are Not a Spammer". Because if you are using your mails to promote your blog. Then one day your blog will be filtered as Spam Blog. It doesn't mean that it will be banned but it has many other meaning that is for serious blogger.
All Search indexing companies check their electronic messaging system time to time by their online Robots. These Robots work as finding duplicates, Linkers to your blog, which is necessity for the page rank determination.
If you are using Yahoo Groups, Google Groups to get a high traffic to your blogs than you are going on a Wrong Side. You are spoiling your own blog and hard working you are doing to maintain your blog. Doing this will filter your blog as spam and Once your blog is marked as spam than all major search engines will remove this from their Indexing either you have a good page rank. Mailing to group mails is a good idea but for a short period it will work only then when you are doing daily mails. But what happens if you are sleeping and didn't get time to mail to group than you missed your traffic trick.
Now think on the other side if you are using right way to popular your blog and hard working. Requesting your friends and all the as subscribe to your blogs daily updates through mail as by FeedBurner or any other service. Try all of the Major Social Book Marking sites Like Digg, Delicious, Raddit, Blinklist, Mangolia, and Many More Sites like This. Then your blog will work when you will be sleeping and your blog will be on the search mode of all major search engines.
In last I want to tell all of you "That Fruit are not coming in a Fort Night It Will Takes Time and Hard Working and One Day Your Will Achieve Your Fruits"
So If Next day you are using your blog make sure that you are Not a Spammer