Newsletters are handled in HotDoodle by the Bulletin Board block set to operate in newsletter mode. The only difference between bulletin boards and newsletters are if recipients can reply and some formatting.
First, insert a block of type newsletter. You will be taken to a screen where you have to enter some board names. Enter the name "Past Issues" and save
Next, subscribe the group you created to this board. Click Manage Subscriptions and then Manage Group Subscriptions
You can now click the group which subscribes to this board.
Configure the Newsletter
You should now click the link to configure the newsletter.
Set "Newsletter Format" to on and unclick the reply options.
Also set your signature and email subject line prefix. Brand yourself, but keep it simple.
Important: To send email, you must configure your site identification and click the "Email Allowed" field.
Bulletin Board Visibility
You need to decide if visitors can see the past issues. If they should not, either put the bulletin board on a page that is not public to them, or config the block and set its access and permissions to "Logged in and Authorized" but do not take the extra step to authorize them.