Solutions for what you want begin to get pricey quickly. There will of course be some integration into your own backend as only you can really know who has viewed what and what "personalized" means in the context of your business. Some solutions to check out:
a) intercom.io and customer.io (both fill a void between a full-on marketing automation suite and a bog-standard esp)
b) marketo & act-on (among others, these are the go-to marketing automation suites -- gets really expensive if you are using them for high-volume consumer messaging though)
These solutions are not priced for direct-to-consumer messaging at volume so caveat emptor.
The deeper the personalization goes, the more you likely it is that you will need to dynamically code the emails and manage deduplication within your app, and then use a standard ESP to deliver the emails for you. Email deliverability, list management and reporting is a pain so use Amazon SES or Sendgrid or Mailchimp or MadMimi (etc.....) to actually get them delivered and track everything.