Step# 1
1- Login to you Blogger.com Account and create a new blog.
2- Then Click Settings > Email and create the email which is shown besideMail-to-Blogger Address. Your email will be like thisyourbloggerid.somewordsthatyouhavefilled@blogger.com
3- Just Below this email setting, Click at Publish emails immediately
Ok Step 1 is DONE.
Step# 2
1- Create a New GMAIL Email ID. (yes! just go and create a new gmail account)
2- Now Join Some yahoogroup of the type of your blog from your new gmail id. (i hope you know how you can join yahoogroup through you gmail account)
3- Forward all the emails of your New Gmail account to the email address of blogger which you have created in Step# 1 (2) i.e:yourbloggerid.somewordsthatyouhavefilled@blogger.com
NOTE= be care full that you are not forwarding more than 20 emails/day to blogger and keep checking your blogger account twice in a month.