SBS2008 suddenly the transport service has been stopping because of backpressure. I noticed that the mail.que and trn.log grow exponentially at a rate of 500 MB in 5 minutes. Queue viewer shows nothing, console get queue shows no messages. I have renamed the queue to .old and restarted the transport service and things run fine for about 20 minutes then bam back again. All the tools for mailflow say things are great. i have disabled our antivirus, checked open relay. i am at a loss! Please help.