Reporting Email User's IP Number

[oldengine]

What variable do I insert into the following phrase to include the sender's IP address? This will knock the socks off from spammers and fraud freaks because when my users report this IP#, it goes into the firewall.

This is a message from $bbuserinfo[username] at $vboptions[bbtitle] ( $vboptions[bburl]/$vboptions[forumhome].php ). The $vboptions[bbtitle] owners cannot accept any responsibility for the contents of the email. To email $bbuserinfo[username], you can use this online form: $vboptions[bburl]/sendmessage.php?do=mailmember&userid=$bbuserinfo[userid] OR, by email: mailto:$bbuserinfo[email] This is the message: $message

EDIT: For answer, see: https://vborg.vbsupport.ru/showthread.php?t=70967