Many times when I am trying to explain something, I am creating a print screen from a Web page (or other region of my screen), cut some area and mark some fragments (for example by red lines).
In most cases I am doing this operations in simple graphic editor (for example MS Paint) and copy/paste it to e-mail program.
Is there any plug-in for mail programs (Outlook, Thunderbird) which can simplify this operation? For example by adding - "attach print screen" - after clicking on it you can select a region of your screen and in the next step mark some fragments.