Magento 1: when is the email added to the quote?

Question

I noticed something interesting today.

I was working on a module that deals with the sales_flat_quote table.

I'm using this table to notify abandoned carts.

However, one of the email in this table does not match any customer nor is present in any order.

I never deleted any order nor customer so I'm wondering at which point the email is added to the sales_flat_quote and how can I reproduce this behavior ?

Answer 1

Email address is added to the quote in conjunction with the billing address. On standard checkout, this is step 1 (or 2, after login/register) of the checkout process.

If a customer completes that step as a guest and abandons at any point thereafter (shipping address, shipping method, payment method, review), you would have the email stored on the quote and quote billing address, but nowhere else.