You have something to discuss, but your team members are scattered in different locations, working on different timezone… One good thing I like about discussion through email is, a loose questions get the feedback from those who has time for a quick reply. This can in fact, save time in face-to-face meeting, yet proven to be more productive. For sure, this might not work in all cases, especially if the team members are not used to this. This is an culture to nurture.
Email discussion can not be done without ‘Conversation View Mode’ in your email clients or Webmail such as Gmail. Too bad, this does not work in Yahoo Mail! This feature allows all email of same discussion grouped together.