Most of the people who use Office Outlook have multiple email account configured in it each having a different purpose, but have you ever thought why do you send the same signature with all of them ? Many of us never thought about it or we just did not look into it.
Office Outlook lets you manage and associate different signature with different mail accounts and it can done very easily. Just to go Options > Mail > Signatures and edit it. This opens the signature creation tool and on right hand you would see a dropdown of all your email id.
Yes a drop down. Meaning create a new signature, select an email account and save it. Next time you send an email you would get the respective signature.
I don’t remember but it should be present in Office 2007. I am using Office 2010 of which you can read about by clicking the link.