I\'m familiar with how to send emails via Google Apps Script (http://code.google.com/googleapps/appsscript/articles/sending_emails.html). It\'s super cool. But is there a way I
The only way to achieve that is by logging with the account of desired email, in your case "event@domain.com" and run the script with it. If you're running the script automatically via a trigger, just set the trigger with this account. If you do not have an account for it, you'd have to create one.
Adjusting the from field is not possible. There's an open issue about this on Apps Script tracker: Issue 172: Ability to send email from users different accounts ("from:" field in gmail)
--update: as one can see by following the link above, this is now possible if the desired address is an alias in your gmail.