Our messaging group looked at this and is going to lessen the header size by adjusting some filtering available in Office 365. What appeared to have happened was Microsoft developed a new enthusiasm for email diagnostics and spam prevention. The newer products became header heavy without an awareness of the impact on other email systems. My guess at least. I was looking thru some of the Transport Rule options and I might have found a solution. It appears I am able to strip out individual header entries Now the challenge is to figure out which header entries are huge and mostly unnecessary ############################ To unsubscribe from the LSTSRV-L list: write to: mailto:[log in to unmask] or click the following link: http://peach.ease.lsoft.com/scripts/wa-PEACH.exe?SUBED1=LSTSRV-L&A=1