Is there a way to limit the internal size of a message, mainly when it comes to attachments for GroupWise? I know how to change the settings in GWIA, but the issue that I'm trying to resolve is a growing frequency of staff using or email system as a file share and sending large size or number of attachments between each other rather than using the shared file storage locations, and I'm frequently having to manually go in and remove these oversized messages because staff won't do it themselves.

Since my GWIA is set on par with Gmail, I'd like to set an internal PO limit of 25 MB and that if someone tries to send a message internally that is bigger than that, that they will receive a message saying that their email is too big... bonus points if I could customize the message.