Action could not be completed. Mail error from Entourage

[dsd17]

One of my clients received an email last night that showed up as a Mail
Delivery error and it has very strange characters in the subject. I've
never seen the characters before. It doesn't look like ascii characters
at all. Anyway, each time you click on this email, an error message
appears that says "action could not be completed. Mail error." If you
hit OK on this message, another one appears in 2-3 seconds. The only
way to get the messages to disappear is to force quit the application.
Has anyone ever seen this before or know of a way to delete that
message from the inbox?
You can't drag it to the trash either. As soon as you click on it, that
message appears.

Specs are OS 10.3.9, Entourage X with latest updates.

 

[nJett]

Have him rebuild/repair the Entourage DB (I believe it's right click on Entourage when you load it?). I've seen something similiar on a clients machine, also with Entourage X. I definitely recommend switching to 2004 (or even away from Entourage completely), Entourage X = craptastic.