You may structure your question and focus on you goal or it will be closed as not constructive / off topic. However, let me show you some screens from the official gmail app (they're in catalan, I'll just translate the important things)
Inbox without any selection
Once you select one or more emails. The upper and lower actionbars change. (Seleccionat means Selected)
As you see, both up and down actionbars change its actions, to show you only the ones you can use in edition mode.
When in landscape mode, there is just one actionbar, in contextual mode. You can add there the actions you need.
More info: http://developer.android.com/guide/topics/ui/menus.html#CAB
EDIT: As told among the figures above, you can define your own actionbar in selection mode, adding a many functionalities as you need. See the second figure. Below the mail list you have a lot of actions you can do. They aren't the same as in normal mode, but of course you can just add the regular actions in CAB. Just make sure they all make sense within the edition mode.