Best free option if you want to use autoresponder

For smaller customer base, Wsija beats MailChimp and others if you would like to use (and why not want to) autoresponder campaigns for new subscribers. Until 2000 users it is the perfect Wp plugin. One important comment: Custom fields would be useful for more data on users. But i read on developer page that it is in the pipe for the next release.
Cheers! Thank you!