The bug has been opened on https://launchpad.net/bugs/97607

"Binary package hint: evolution

My school doesn't allow outgoing SMTP mail, so I have my computer set to send mail to localhost, and whenever I SSH in from another machine, portforwarding takes over, and the mail gets out. No problem. But when I don't have an SSH tunnel open, evolution tells me that it can not send mail (as expected), but there is an ugly box around the message.

http://librarian.launchpad.net/7038259/Screenshot-Evolution%20Error.png
Screenshot of mail delivery failure

That bounding box should go away as I've never seen that anywhere else in Gnome.
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> Thanks for your bug report. What is not HIG compliant about the dialog?
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http://librarian.launchpad.net/7047398/Screenshot-gnome-mount.png
Normal error dialog

Observe how there is no bounding box around this error dialog that Nautilus creates when I attempt to unmount a volume that I don't have rights to. No other Gnome app I've seen creates the bounding box visible in the previous attachment."