I use MS outlook at work and you can actually open incoming emails, edit the subject line and save it, used this a few times as a quick way to tag my emails on

I use MS outlook at work and you can actually open incoming emails, edit the subject line and save it, used this a few times as a quick way to tag my emails on what needs to be done with them, e.g.: - [FOLLOW UP] Lorem ipsum dolor... - [ASK MICHAEL] Lorem ipsum dolor... - [INCLUDE IN PROPOSAL] Lorem ipsum dolor...