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BlackBerry Enterprise Email

On the Home screen, click the Messages icon.
Press the Menu key > Options.
Click Email Preferences.
If the Message Services field appears, change this field to the appropriate email account. This will allow you to select the corporate email address or one you added.

If the Use Auto Signature check box is not selected, select it.
The default signature can be used, or a custom signature can be entered.
Press the menu key > Save.
Note: The new signature is added to the email after the message is sent.