Transport service high CPU usage causing mail flow delays

Hi Mason Mcgrath

Thank you for reaching out to Microsoft Q&A

Based on my research, this typically occurs due to Transport back pressure or a stalled Transport agent. Back pressure throttles mail flow when disk space or memory on Transport paths crosses thresholds (Event 15006). Event 7012 often relates to log scanning overhead. High CPU can also result from anti-malware scanning or RMS/IRM decryption processes within EdgeTransport.exe.

Link reference: https://v4.hkg1.meaqua.org/exchange/mail-flow/back-pressure

Therefore, you can consider follow some options below to see if they can mitigate your issue:

1.Check Back Pressure metrics

Use Get-ExchangeDiagnosticInfo -Process EdgeTransport -Component ResourceThrottling yo confirm if disk or memory thresholds are triggering back pressure. Free space on %ExchangeInstallPath%\TransportRoles\data\Queue\ and ...\data\ should exceed Microsoft’s recommended limits. If needed, move the queue database and content conversion directories to a larger, faster volume via EdgeTransport.exe.config. As stated in https://v4.hkg1.meaqua.org/en-us/powershell/module/exchangepowershell/get-exchangediagnosticinfo?view=exchange-ps

2.Validate receive connector bindings:

Ensure only FrontendTransport connectors listen on TCP/25. As stated in https://v4.hkg1.meaqua.org/en-us/exchange/mail-flow/connectors/receive-connectors

Hope my answer will help you

Best regards.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".     

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.