Hello Jon Mikel Inza,
Events module supports Publication and Expiration date as a metakeys. As for the notification : You can subscribe for Application_Start of your Global.asax and and ContentManager.Executed handler. Then you will have access to the content item objects. You need to create a new instance of EventsManager and loop through each content item and use GetMetaData method to get the value of Expiration_Date. Afterwards you could compare the Expiration_Date with DateTime.Now and if DataTime.Now is greater than IContent Expiration_Date you can send an email message. Note that the send email logic will be executed only on a request to your website. Othwerwise you need to implement some ticker.
We will have buil it schdeuled services from Sitefinity 4.0.
the Telerik team