title: Setting importance on emails sent by Logback SMTPAppender
body: <p>I'm using an SMTPAppender in Logback to send messages from automated jobs when they complete successfully and when they encounter errors. I'd like the emails notifying us about errors to be sent with high importance. How can this be done with Logback/SMPTAppender? If it can't be done out of the box, does anyone have a home made solution for this problem to share?</p>