Pipeline Tracing is a new feature which was introduced in Exchange 2007 and is present in 2010 as well. It helps an Exchange admin to figure out issues as an email passes through the transport pipeline on HUB or Edge transport server. The feature is turned off by default in Exchange 2010.
Pipeline tracing only traces an email from a sender (user who has issues), whom we specify as Exchange admins. By default, no emails are traced and there is no “PipelineTracingSenderAddress” configured.
The default location for pipeline tracing logs is within the “TransportRolesLogs” folder. The folder can be changed by running the command below.
Set-TransportServer “servername” –PipelineTracingPath “path”
Let me explain the process of tracing in a bit detail. As an admin, I want to trace what happens with the email sent from my account to my family (Chakka & Chakki) and what actions are performed by different transport agents.
First step is to configure my email address as the “PipelineTracingSenderAddress” using the Set-TransportServer cmdlet.
Set-TransportServer “hewexch” –PipelineTracingSenderAddress “Rajith.Enchiparambil@theucguy.net”
Second step is to enable pipeline tracing (I am happy with the default location of logs folder).
Set-TransportServer “hewexch” –PipelineTracingEnabled $true
It is not recommended to run pipeline tracing for too long, as lot of log files are created and it will fill up your disk space very soon. As the content of the email is copied to the log files, permissions on the logs folder should be strict.
Let me send an email from my account to my family and see whether the trace completes successfully. Yes, there is a missing “e” in the subject ;)
A look at the pipeline tracing logs folder shows 17 log files for one message.
Opening the last log file using notepad shows that the agent which processed the message is “Outbound Trust Agent”. It gives other useful information as well for troubleshooting.
Scrolling the log file towards the end reveals the content of the email.
If you have a user who has issues with transport agents (say disclaimers are not getting applied, emails are not journaling, certain transport rules are not getting applied etc), enable pipeline tracing for the user and look through each log to troubleshoot the issue.
Once the issue is resolved, it is advisable to turn off pipeline tracing and delete all log files that was created, as it copies the email content. Happy troubleshooting 
Transport pipeline enabled for exchange 2016 internal user. mails snapshots are available, but when open the email it is blank. is there any option to know which agent applied what and when.
when email sent from telnet, snapshot emails are readable in outlook and understand what agent applied
How does this help in tracing attachment stripping issue?
Can you be a bit more specific Rakesh?
Do you have a third party message hygiene solution in the mix?
Thank you Rajith, is this has been most helpful to me. This page was recommended to me by Microsoft TechNet
“https://social.technet.microsoft.com/Forums/office/en-US/8f7cbfce-919f-46c7-8730-7c6b9fbe6e3b/messages-hitting-rules?forum=exchangesvrsecuremessaging”
Would this work using an external address (External Sender emailing internally) ?
Hi,
I just checked your blog to get some help for exchange delay in message delivery issue. if you could interested in helping me please share your contact details so that i can call you.
Regards
Raghavendra Sahukar
Post your issue here and I will see what I can do.
Thanks