I never got it working. On my system it just hangs smtp. This is the script I ended up with but I don't really have a dev background, Just correct syntax/spelling and adjusted for have route domains on my system
when CLIENT_ACCEPTED {
set caddr [getfield [IP::client_addr] % 1]
log local0. "Client addr: $caddr"
STREAM::expression {@^EHLO.*\r\n@@ @^HELO.*\r\n@@}
STREAM::enable
}
when STREAM_MATCHED {
set mstring [STREAM::match]
log local0. "STREAM_MATCHED: string: $mstring"
set replacement [string range $mstring 0 1]
append replacement "LO $caddr\r\n"
log local0. "STREAM_MATCHED: replacement string: $replacement"
STREAM::replace "$mstring $replacement"
event STREAM_MATCHED disable
}