Can you view the automated transactional emails that have been sent by the system like order confirmations, password forgotten-mails and more? Is there some kind of a mail log which you can view afterwards?
The new 1.9.1 Email System leverages two database tables to queue, process, and log transactional order confirmation emails sent after customers checkout:
core_email_queueThis stores data relating the emails that are sent for order confirmations
core_email_queue_recipients- This stores the email addresses of the recipients of the emails stored in
Troubleshooting issues with this new functionality can be difficult. The link above is fairly technical but covers the key areas. I also have had success with following this process in my own troubleshooting, though the issues I ran into were specific to my environments so your mileage may vary.
In magento 18.104.22.168 there is email queue table. In previous magento versions most probably you can find only was email sent or not. In tables sales_flat_* (order/invoice/shipment) there is such field as 'email_sent'. Which has only true/false value. The email address you can also find in same table.