Mail behavior with multiple accounts

Hopefully, I'm just having a "Duuuh" moment, but so far, I have not figured it out and hoping someone else has. I have multiple email accounts in the Mail app on my MacBook Pro. Annoyingly, if I right click on "Trash" and select "Erase deleted items...", it will erase deleted items from every Trash folder in every email account I have within Mail. Example: If I empty the Trash folder on my Microsoft LIVE email account, it also empties the Trash folders in my Gmail account and my GMX account. This seems like it would be a basic setting somewhere within Preferences, but I can't find it. Anyone have any tips/tricks? Thank you!!