I would like implement a user /user group list for sending the newsletter. I would like to know which files should i edit ?

Other than that, I would like to know if there are any websites that provides free extension package for dotnetnuke?

 

Thank you

If I understand you correctly, this is setup using the security roles.

All you have to do is create a new security role, such as 'special promotions' and assign that security role to the users you wish to send this particular newsletter to.

In the newsletter module it lists the security roles for who you would like to send the newsletter to, so just tick the 'special promotions' security role.

Currently I do not know of any free extensions for the email module, there are however email modules available for purchase on snowcovered.

Hope this helps, thanks,