Are there any Cydia tweaks or settings to have a different notification for emails from a certain sender? If not, the only workaround I can think of is to set a rule on the Exchange server to send a text message when an email from the desired sender arrives. Then make a custom ringtone for those text messages with BiteSMS. This obviously isn't very elegant and could result in a lot of text messages (although I have unlimited). Any other clever ideas are appreciated.