Is there any way to have it so if I delete the e-mail off the Yahoo account, it will delete it on the Outlook express account? It doesn't do this and I can't find any way to make it do this....
If there is, then it's through Yahoo, not Outlook, for the reasons mwest stated.
However, I remember that when I used Hotmail, MS had it set up so that I could have Hotmail account folders in my Outlook folder tree, and they were set up to sync with Hotmail. If I deleted an email in either place, it would be deleted on the other. Naturally, this was probably because of the MS connections, so I no idea if this is possible with Yahoo.
The only thing I can think of is to do some deep searching into Yahoo's options and settings, because I don't think you'll find them in Outlook.