The new icon is an arrow pointing down to an inbox tray, unlike the old one that looked like an envelope.

Any way to change it back to envelope?

The new icon is virtually hidden in the taskbar due to its small and dark design, a serious step backward in design. The previous envelope design was far better, and change for the sake of change doesn't always reflect well on the "changer" !

So how do I change this back to the way it was? If its not currently possible, can an option be introduced to do so in the next update. Or is there an add-on under development to bring back the icon and font add-on that no longer works?

The icon has changed from an opaque envelope, to an arrow/tray, to a transparent envelope, all in the last few months. I don't know of a simple way to change it, as it probably requires hacking the TB exe. I also haven't seen any recent Requests for Enhancement reports on Bugzilla, which is where you can bring this to the attention of the developers.

I have mentioned elsewhere that another option is the Unread Badge add-on, which shows a count of unread messages in the Windows taskbar icon.

Now this is interesting info. I'm going to look further. Thanks, seems like a minor issue I know but was just wondering about it.

The Unread Badge is a partial fix, thanks. At least its visible whereas the 'new' envelope symbol is mostly hidden (90% dark on dark background). Having trouble accessing Bugzilla with my login, otherwise I'd post there.

Yes PLEASE make it able to revert to the old design, this looks absolutely horrible imho :(