PHP Web Service Program (SOAP - WSDL)

My web application queries a web service and retrieves results when the user enters a search term and clicks search. I want to improve this process as follows: 1) The program should run as a cron every 7 days. I will set this up on the server so you just have to tell me the URL. 2) It should only check for articles that have been released in the last 7 days. The web service offers a built in method of doing this. 3) For each article retrieved, the program should check the database to see which users are interested in that article and it should automatically send an email to the user notifying them that there are new articles of interest and including the title, link and abstract in the email. 4) The user should only receive 1 email so if there are 3 articles of interest to them then they should receive 1 email which includes the title, link and abstract of all 3 articles. This must be completed in a live environment. I will provide hosting and database and you do not need to create new users, this will be done for you.