One thing that one must not forget is also integration with your existing website. If your running on Joomla, WordPress, Drupal or such likes, better you find how the user integration will go with your CMS and one of those email services. You don’t want the client to have to register for your autoresponder on one form and then have to register a second time for your website! You may find that plug-ins to do such things might restrict your choice, check it out first or consult with your webmaster!
Now, you can automatically send highly relevant emails encouraging them to buy the product or service they were considering. Customers who received multiple abandoned shopping cart emails are 2.4 times more likely to complete the purchase than those who receive only one followup email, according to Experian. Try sending the first message one day after, a second message 48 hours after, and possibly a third message within three or four days of abandonment.