Capture traffic logs for a particular User mail address

Hi,

 

Can we capture traffic logs from the F5 for a particular user mail address?

 

We have configured SMTP relay on the F5, through which some application is sending test mails using a particular user mail address.

 

We are trying to find out the application which is using the SMTP relay. When checked on the Exchange server end, all they could find was the SNAT IP of the F5, which is configured for the VS.

 

Kindly assist.

 

Regards, Allwin