Gmail 4.2.1 for Android adds easier resizing, swipe features and more
Source: http://www.engadget.com/2012/12/03/gmail-4-2-1-android/
That leaked Gmail APK we peeked at a month or so ago turned out to be right on the money. Google has just released version 4.2.1 of the Gmail app for Android, which does indeed add pinch-to-zoom on individual messages and swipe (left or right) to delete or archive. There are a couple of features we didn't see in the initial leak though, which are the ability to "auto-fit" a message to your phone's screen and a new thumbnail view of attached images -- you can then tap a thumbnail for a swipeable gallery. If still pictures aren't your bag, it's finally possible to attach phone-captured videos to an email as well. This version of Gmail is only available for phones with Android 4.0 or higher however, so older devices might be out of luck. If your device qualifies, you can download the new version of Gmail right now from the Google Play store.
Source: Gmail (G+), Gmail (Google Play)