reducing filesize for outlook express

For some reason our son is suddenly unable to reduce the filesize of photos he tries to mail us using outlook express.
The problem is windows isn't showing the dialogue box asking if he wants to reduce the size as it should/used to, it just attaches the full sized picture with the full 2-3 mb per picture filesize that comes with it. It's not that he doesn't know how it should work.

Is there an option that may have turned the process off and how would he reset it?

Windows Xp home premium.

The last software installation was the drivers and software that came with a new Epsom all in one printer/scanner/copier

Thanks in advance.