The behaviour the user wants is to open a link. The idea of displaying the email again beside the webpage is valuable, but to the user their preferred browser is more valuable. Realistically, they already have their browser open, if they do anything other than read and close the web page their browsing is now split across two browsers without rhyme or reason. Say they switch to Excel and need to switch back to the webpage to double check something, it'll immediately be "oh, this one page is open in Edge, not Chrome where I first looked".