https://chrome.google.com/webstore/detail/gjnmclkoadjdljnfmbnnhaahilafoeji
and a GmailTeX Chrome extension at
https://github.com/kristi/GmailTeX-Extension
so perhaps these will work for you. There is a discussion on
mathoverflow that lists these as well as some other approaches at
http://mathoverflow.net/questions/22141/how-do-i-see-latex-math-on-any-web-page-and-in-email
Hope that helps.
Davide