Mail dispatching application

Hi, I provide a system of add to cart service to the customers linked to the website store.nike.com. When Nike launches a release a specific day, we run our service and when it works well for a customer, he receives an email informing him that our service did successfully carted the wanted shoes and he has to log in on the [login to view URL] to proceed to the checkout of their shoes. The email contains the following information: - The model of shoe which is carted - The size of the model which is carted - The information (login/password) of the main account of the customer To increase the chances of the customer to get the shoes he wants, we link to his main account several backup accounts. As for your main account, when our service works well for one of the backup account which is linked to his main account, the customer receives an email with the following information: - The model of shoe which is carted - The size of the model which is carted - The information (login/password) of the backup account which is linked to the main account of the customer Regarding this behaviour described above, sometimes it happens we have sent: - 9 emails to a customer X informing him that we carted the model A with the size B - 0 emails to customer Y who wanted the same model and the same size than the customer X - 0 emails to customer Z who wanted the same model and the same size than the customer X Following this sample described above, I would like to have a software which dispatches automatically the emails to the different customers in order to have for instance: - 3 emails to a customer X informing him that we carted the model A with the size B - 3 emails to customer Y who wanted the same model and the same size than the customer X - 3 emails to customer Z who wanted the same model and the same size than the customer X To permit that, I'll be able to provide you as inputs: - the list of the different generic mail addresses I use to send the emails to the customers - an input file containing the list of the customer mail addresses and for each of them the wanted model and the wanted size Regarding the configuration of the software, I would need to be able to set the ratio of mail I want to send by customer (3, 5, 10, ...) and to load the file containg all the information permitting to do the mail dispatch between the customers. Hope my specifications are clear. Let me know via a private message if you need further information. Thanks in advance.