IMHO: These types of things are not successfully dealt with via email. If you are in search of an email template, you are on the wrong path.

Your raise or lack thereof will be determined by one or two people. (a person will make the decision and perhaps their superior will need to approve it). If you don't know who the person is, your first task is to find out. Let's assume you know who the person is. If two people have a healthy relationship and there is an important issue to discuss, the issue will be raised and discussed in person. If you don't have a healthy relationship with the person who will make the decision, fix it.

IMNSHO: If you are not willing to do the above, by far the most effective email template to ask for a raise will be: "Dear X, I am writing to apply for the web developer position at company Y (...)"