I have 4 different email addresses currently being forwarded to gmail (actually 3 and then my gmail address). I have it set up in gmail that when I reply it gets sent from whichever address the message was sent to. This works perfectly.

Now however with the unified mailbox (and this actually happened before that), whenever I reply to a message from any account in gmail using the mail app. it gets replied to from my gmail address and not the correct one.

Does anyone know how I can fix this? Other than using the gmail web app.