As long as Evolution is the default mail application in Ubuntu, the current (envelope) icon works better. The icon serves two different purposes:
1. Tell a user what the program does that is run if he clicks on it (in this respect the original evolution icon clearly wins).
2. Help a user find his way to an application that is suited for the task the user wants to do. In this respect any default mail application should be clearly labeled as such, without clutter from other, secondary features.
In this case I think it's more important that a user can find 'the' email application quickly so I wouldn't change the icon. It would be a whole different case if Evolution wasn't the default mail software.
1, seriously, i do not thing that the original icon makes it harder for the user to find the function hes after,
2, and since evolution is also the default calendar program and it handels ones contacts, memos, tasks, then having the icon only represent the mail funkrion like in OSX (where the functions are seperated into different apps) is flawed.
Vahan Harutyunyan(Brainstorm moderator)
wrote on the 8 Nov 11 at 09:58
Please file a wishlist bug report against Evolution for this issue or direct your suggestion to the Evolution developers http://projects.gnome.org/evolution/