How do you update the email address associated with a billing invoice?

We send a small amount of billing invoices out as attachments in emails.  We would like to expand the use of this process to save on time and postage costs.  Currently however, the email address associated with the billing invoice shows as 'finprodp@cabq.gov'.  Most customers will delete the email as they do not recognize the email address and think it is a junk or spam email.  External customers do not know who or what 'finprodp' is and why they are getting an email from that email address.  There must be a way to update this so the from email address makes more sense and is a little more recognizable to the external customer such as: