I am wondering if anyone has any advice on sending an email to another person in another department when a field is updated.

What I want done:

We have a price comparison section in the account page in the CRM. When a salesmen uploads customer's invoices from our competitors, I want an email to be sent to someone in another department to be alerted that the invoices were uploaded so they can do a price comparison. Then when the price comparison finished and is uploaded in the respective field, the salesmen should be emailed alerting them it is there/completed.

Does anyone have any solutions to this?