Usually Exchange stops delivering becouse the system runs down of resources..
This is the Microsoft reference “https://docs.microsoft.com/it-it/exchange/mail-flow/back-pressure?view=exchserver-2019”
This is an example of Event: “Microsoft Exchange Transport is rejecting message submissions because the available disk space has dropped below the configured threshold…”
![](https://marcoschiavon.net/wp-content/uploads/2020/03/event.jpg)
Command to check the “pressure” :
[xml]$bp=Get-ExchangeDiagnosticInfo -Process EdgeTransport -Component ResourceThrottling; $bp.Diagnostics.Components.ResourceThrottling.ResourceTracker.ResourceMeter
![](https://marcoschiavon.net/wp-content/uploads/2020/03/Back_Pressure_Check-1024x615.jpg)
Ok We are under pressure…
I’ll go to disable the “back pressure” functionality.
Open with the editor: \Program Files\Microsoft\Exchange Server\V??\Bin\EdgeTransport.exe.config
![](https://marcoschiavon.net/wp-content/uploads/2020/03/Screenshot-2020-03-03-at-15.05.58-1024x384.jpg)
Now we need to add, “< add key=”EnableResourceMonitoring” value=”false” />” under, “appSettings“
![](https://marcoschiavon.net/wp-content/uploads/2020/03/disable_back.jpg)
Now restart the “Exchange Edge Transport service“