Scheduled Mail send application

I want a web application that I can program an automatic schedule send of email το variable destinations. The application must be able to set specific periods to send emails, ex. Every month, every 6 months, every year or every 2 years depending the destinations. Also must be able to change or add content of emails that will be send or use 3 or 4 specific templates which I will be able to add in admin settings. Contacts will be as I mentioned variable each time so I must be able to set destination manual if needed but also must be able to use contact list in application. Contact list will be able to add contacts to it if want but also must be able upload the in a .csv file if I want. All contacts will also get automatically an id number so they can’t be replaced when uploading list. Mail server settings will be set from us and can be changed also from us. And must be able to see all programed emails in application and also as I said above must be able to add new plan if I want.