On Mar 9, 2007, at 11:22 AM — 3/9/07, Christopher Wilson wrote:

> All-
>
> This has been happening here at GW, and not just with Listserv.  
> Users of other mail clients (Thunderbird and Sun Java System  
> Messenger Express specifically come to mind) have been sporadically  
> reporting similar issues for over a year. We were able to push a  
> fix for managed clients via our patch management systems, but users  
> whose desktops are not centrally managed still run into this from  
> time to time.

I suspect that if the recipients of one of those blank messages view  
the message in plain text mode, its contents will show up.