There are several ways to send emails to contacts from Stager. An email is of course sent to the ticket buyer when a ticket is purchased, but you can also send marketing emails and emails with free tickets. Read more about sending mailings.
Under Settings - Ticketing - Ticket shops you set the text of the ticket e-mail.
Email addresses
If you send a mailing using Marketing - Mailings, we use the sender address and name you entered here. We recommend entering a general, or company-wide address here.
Make sure your email domain is verified, so emails have a smaller chance of ending up in SPAM. Read here exactly how to do that.