How to set multiple e-mail signatures on iOS 6
Having only one e-mail signature is a thing of the past for iOS. Here's how to set an e-mail signature for each e-mail account on your iOS 6 device.
The latter will let you to customize the signature for each account, allowing you to set a signature for your personal e-mail account and another for your work account.
Now, when you send an e-mail, iOS will automatically apply the proper signature based on the account you're using to send the e-mail.