I use Gmail as my primary email, but I also have a Google apps account that is forwarded to my Gmail. On the computer, I have it set so that I can compose a new message and change the from field to be either from my Gmail account or my Google apps account. This way I keep everything in my Gmail account (so I can search for both sent and received messages later) but make use of both email addresses.
On my Droid X, I set up both accounts in the Gmail app. Now, from within my Gmail account, I can compose a new message from either my Gmail or Google Apps account. That part is good, but the same functionality does not carry over to replying to messages. If someone sends a message to my Google Apps account, I receive it in Gmail but when I hit the "reply" button I can only send from my Gmail address. Is there a way to reply, from within Gmail on my Droid, from the Google Apps account?
This makes sense, since the email that's getting forwarded is going to your main email address, so when you hit reply it's going to send it out from that one. As far as I know there isn't a way to reply from a different address than the one it was sent to using the mobile app.
I have a normal Gmail account and a Google Apps account for work that are both set up on my DX as well. I just have my Apps inbox and my Gmail inbox and use them both completely separate with no forwarding and everything works just like it should.
I guess I was hoping that since I can do it in normal gmail I'd be able to do it in the app too. I could use both separately but I want to be able to have all messages including sent messages in my gmail.