Autoresponder is a must for internet marketing. You must hold your prospect contact in order for you to do follow up.
Below are some popular autoresponder
- getresponse (usd15/mo for 1000 subscribers. free 30-day trial)
- mailchimp (free forever for first 2000 subscribers. But with autoresponder add usd10/mo)
- mailerlite (free forever for first 1000)
- sendgrid (free first 2000 subscribers)