Or any other mail client really. What I don't get is why they stripped it out from the browser (I didn't take up any disk space really).
edit: I really hope they don't take out RSS reader functionality out as well. I never got why other browser didn't support such basics when it came to browsing.
Opera Mail (previously M2) is probably still using the Presto engine (and the old interface) as they seem to have just extracted it from previous releases. Thus it is incompatible with their new version and Chromium.
Switching to Chromium was a big mistake IMO, seeing how inferior, unstable, and slow the new Android app is compared to the original. I get it, they had to cut costs, so they fired a bunch of people and gave up their proprietary edge. It just seems to have been the wrong decision because they took away one of the core features that used to make it great (at least with regards to the Android app): speed.
From what I've read the desktop version lost basically everything that was special to Opera. I know it's early builds but I think many features won't make it back.
edit: I really hope they don't take out RSS reader functionality out as well. I never got why other browser didn't support such basics when it came to browsing.