Using LINQ to do email templates

So recently I was working on project where a client wanted to have customisable email templates which could be merged with data from their database so we store the email as an XML document and have a series of placeholders within it to allow easy editing to customise the wording, layout, etc. But because there's quite a lot of different email "data sources" we wanted a nice and easy way so we didn't have to constantly write merge methods, having a single method which handles it all is the best idea.