Hi, mail_logs already logs the sender IP address and sender/recipients email-addresses.
Snippet from the mail_logs "for a test e-mail that i send in our local labs" i used BOLD for the sender IP/sender/recipient.
Thu May 26 12:24:06 2016 Info: New SMTP ICID 2006 interface management (10.48.78.10) address 10.48.78.35 reverse dns host _ldap._tcp.dc_msdcs.ironport.local verified no
Thu May 26 12:24:06 2016 Info: ICID 2006 ACCEPT SG WHITELIST match 10.48.78.35 SBRS rfc1918
Thu May 26 12:24:06 2016 Info: Start MID 2781 ICID 2006
Thu May 26 12:24:06 2016 Info: MID 2781 ICID 2006 From: <raed@munich.local>
Thu May 26 12:24:06 2016 Info: Alias match: MID 2781 RID 0 recipient raed@amman.local mapped to ['mahmoud@amman.local']
Thu May 26 12:24:06 2016 Info: MID 2781 ICID 2006 RID 0 To: <mahmoud@amman.local>
Check the following How do I search and view the mail logs on the ESA
Regards
Raed