e-mail notifications about changed wiki paged are halted until a user downloads a newer version of the page while logged in.
If one has seen the page already while not logged in as this user, or if one does not want to have he entire page transferred over the net when reading his e-mail, etc., one should have a lightweight link in the e-mail body telling the wiki to return the watched page to the "seen" state. ("continue notifying me")
Likely, this could be had similarly to the mechanism putting a page on ones watchlist via the star icon of the vector skin, which also does not reload the page.