Promote up-sells/cross-sells. You can even set up an autoresponder sequence for someone after they purchase and get repeat customers. Depending on the products you sell, you could offer an upsell, or cross-sell related products. For example, if someone buys a digital camera, you can offer to add a lens, a tripod, and other accessories to their order before it ships. Or, if you sell products that people buy frequently (like food or disposable items, like diapers), you can automatically send them offers for new items when you know they’re about due for another order.
For example, if you set up an autoresponder with an interval of 24, and you receive an email from email@example.com at 8 am on Monday, the autoresponder will respond to his message immediately. If, however, firstname.lastname@example.org continues to email you throughout the day, the autoresponder will not send him another response for 24 hours after his initial email (in this case, 8 am Tuesday). If he emails you again after the 24-hour interval expires, he will receive an auto response.
The first autoresponders were created within mail transfer agents that found they could not deliver an e-mail to a given address. These create bounce messages such as "your e-mail could not be delivered because..." type responses. Today's autoresponders need to be careful to not generate e-mail backscatter, which can result in the autoresponses being considered E-mail spam.
We also love how consistent the design of Uber's emails is with its brand. Like its app, website, social media photos, and other parts of the visual branding, the emails are represented by bright colors and geometric patterns. All of its communications and marketing assets tell the brand's story -- and brand consistency is one tactic Uber's nailed in order to gain brand loyalty.