Mail Not Delivering --REALLY BAD!!

[Mailing Lists]

Hi,

Thanks for all your replies, but this is starting to get serious! 

I have a bunch of clients who are expecting mail, and I don't know what
to tell them. 

Here is the situation:

Mail stopped being delivered last Friday with no notice!  I even sent
test emails right from my local command promt to myself and they went
nowhere! i.e. #echo test |mail -s test lists at gmnet.net

Where did this mail go?  Right now, I am running sendmail w/o
mailscanner at all! this is the only way mail gets delivered! 

Please Help!
Rick