Using Word Mail Merge to send emails

[BadgerRoad]

I am trying to use Mail Merge to send out personalized documents via email which I do have working to a point. The emails go out and indicate they are from my primary email account. I have an alternate email account and I would like the emails to be from the alternate email account. I have both email accounts set up in Outlook but I can't figure out how to indicate they are sent from the alternate account.
Any help is greatly appreciated.
Thank you.