AutoTweetNG sends your generated AutoTweet content as E-Mail to a group, mailing list or something else.
AutoTweetNG Mail Channel is not for create mailing lists, manage your subscribers, send Newsletters or something like that.
This channel is simple to setup:
Go to the tab 'Channels' in AutoTweet backend and push the 'New' button.
Set the channel type
Enter your mail account data, mailing list data o group data and that's all
What types of data gets entered? Is it looking for an email address? Perhaps a Joomla user group? I don't understand what this channel does.