Entourage issue

My boss is under the impression that Entourage (or maybe it's MAC that saves them...i use PC and know virtually nothing about MACs) must save copies of her emails even after she deletes them because on a few occasions when Entourage has crashed and has had to rebuild it's database messages she has deleted are being pulled back into her inbox.

She says if she signs into our company webmail and deletes these messages there they are gone for good so it feels like an Entourage issue to me.

Is there a folder somewhere on her computer where these deleted emails are stored? Is it only pulling back emails that are in her recycle bin?

Thanks!