If you tell a customer that you’ll be sending a confirmation email, they’ll probably expect to get it right after the transaction is completed. After all, that’s how Amazon and other big sites do it: submit your order, and they send you a confirmation within 15 minutes or so.

However, I ran into one example where the site promised a confirmation, and days went by with no follow-up. Perhaps their system generates the confirmation message after some other event happens, like shipping a physical product or welcome packet. Whatever the cause, they need to set expectations properly, rather than leave customers guessing.

When people hear “confirmation email”, they assume it means a message is coming right away. So if your systems or processes can’t meet that expectation, just say so upfront. All it takes is a little bit of text on the thank you screen, e.g. “We’ll send you a confirmation email in 24-48 hours.” By providing this extra level of detail, you’re telling people what to expect — and they won’t think you screwed up by failing to send the confirmation instantly.