mail it in

mail it in (third-person singular simple present mails it in, present participle mailing it in, simple past and past participle mailed it in)

1. Used other than figuratively or idiomatically: see mail,‎ it,‎ in.
2. (idiomatic) To deliver a performance without commitment or effort, with lackluster results.
   • 2008 January 11, Bill Keveney, “Idol tries to get its groove back”, in USA Today, page 1A:

     "I do think the judges mailed it in during Season 6, relative to previous years," Welton says. "Simon needs to be nastier. […] "

   • 2009 January/February, Keith Bellows, “Go, But Go Green”, in National Geographic, volume 26, number 1, page 22:

     So when you have to write two columns a week that are going to be read by a lot of people around the world, you can't just mail it in. You're thinking all the time.

   • 2010 May 25, Joe Cowley, “Crunch time comes early; Sox 7 Indians 2; Peavy^s point: Next month is make or break”, in The Chicago Sun-Times:

     Listen, we're not mailing it in, we're trying to get better.

• phone in

• mailed-in