Vtiger CRM allows you to create two types of email campaigns:
Autoresponder email campaigns are the emails that you send in response to the contacts’ reaction to your previous email campaign. They are sent automatically when triggered at the scheduled date and time. You must set up trigger conditions, the date, and the time at which they must be sent.
For example, you send a Christmas offer to your customers through an email campaign. When they buy a product from the offer, you send them an autoresponder email with a Thank You note. The autoresponder is triggered automatically when they buy a product from the offer mentioned in the email.