IMAP via GWIA will allow very large draft messages to use up all available disk space

Summary: IMAP client "save as draft" circumvents file size limits and can cause the host File System to fill up completely.

Steps to duplicate:

Set up Thunderbird mail client pointed to GWIA IMAP server.

Compose a new message and add a 2GB or larger attachment.

Save the message as a draft.

/wpgate/gwia/000.prc/gwwork folder will show a file created that will grow to more than 2GB in size.  The client may throw errors and it seems that each time it does a new file is created in the gwwork folder that will also grow to more than 2GB in size.  This repeats until the disk if full.

Note:  This doesn't happen if the mail client is configured to store draft messages on local drives.  However the default is to store drafts on the IMAP server.  This leaves us in a vulnerable situation as a single user can bring down the GWIA server by trying to email a copy of the latest Marvel Avengers movie.