Have you ever had a strange build up of temporary files on your Enterprise Vault Server? Strange in that they're all the same size, and appear in a long row of sorts? Well the explanation might be that Enterprise Vault is trying to process a problem message. The situation is described in this technote:
http://www.symantec.com/docs/TECH206368
I know that issues like this are super tricky to find, and to fix, but really this could lead to quite a bad situation on your Enterprise Vault server. Have you ever had any issues with stuck/problematic messages, let me know in the comments below: