Send mail after 80 minute when Ios app into Background mode?

i am working on ios app where send the one alert mail after 80 minutes when app into background mode. i set the one local notification that popup at 75 minutes and after 5 minutes of local notification popup , if not tap to that notification then mail send? i try most for alive my ios app for 80 minutes but my app terminate.please give the advise for that.thanks.