We are now in the year 2017 and any exchange admin will know this by the back of their hand but as little as I touch Exchange now (either because it’s rock solid or we’ve moved to Office 365), I always have to Google it. So this is just a reminder for me in the future.
A customer had a backup issue over the past weekend due to an unfortunate set of circumstances. As a result, their D: was getting full. They had 15 Gb left of 600 Gb total but the probably well known feature of Exchange called Backpressure prevents your hard drives from filling up due to email transport and their mail stopped flowing. I needed to get their email working ASAP while a backup completed in the background. An easy and temporary fix for this is to disable transport resource monitoring. This can be done by modifying the edgetransport.exe.config file.
Modify this line:
Restart the Microsoft Exchange Transport Service.
Just be sure to re-enable Resource Monitoring after you’ve solved the problem that got you here or someday soon you’ll be in a world of hurt. Also, get some disk space utilization alerting going and stop waiting for things to break.