SMTP Sensitivity Tag

I was testing out my rule it work fine for small messages but when a large message comes it it casue the TMM system to core. I have open a case with support. My first guess is somehow I am stepping on memory from another run of the rule or something like that. Any help would be great. Thanks

when CLIENT_ACCEPTED {
   use pool mailhost1v
   set clienttcpdata ""
   set rec "1"
   TCP::respond "220\r\n"
   serverside {TCP::respond "/r/n"} 
   TCP::collect 
}
when SERVER_CONNECTED {
   set servertcpdata ""
   serverside {TCP::respond "/n"}
   serverside {TCP::collect}
   log "Server Connected"
}
when SERVER_DATA {
   set servertcpdata [TCP::payload]
   TCP::payload replace 0 [TCP::payload length] ""
   clientside {TCP::respond $servertcpdata}
   clientside {TCP::collect}
   clientside {TCP::release}
   serverside {TCP::respond $clienttcpdata}
   log "$servertcpdata"
}
when CLIENT_DATA {
   set clienttcpdata [TCP::payload]
   serverside {TCP::respond $clienttcpdata}
   log "USER_RESPONSE"
   log "Client Data = $clienttcpdata"
   clientside {TCP::payload replace 0 [TCP::payload length] ""}
   TCP::release
   if {$clienttcpdata starts_with "HELO"} {
        set smtphelo $clienttcpdata
        log "Helo = $smtphelo"
   } elseif {$clienttcpdata starts_with "MAIL FROM:"} {
        set smtpmailfrom $clienttcpdata
        log "Mail From = $smtpmailfrom"
   } elseif {$clienttcpdata starts_with "RCPT TO:"} {
        if { $rec == "1" } {
           set smtpmailto $clienttcpdata
           set rec "2"
           log "hi"
           log "Mail To = $smtpmailto"
        } elseif { $rec == "2" } {
           set smtpmailcc $clienttcpdata
           set rec "3"
           log "CC = $smtpmailcc"
        } elseif { $rec == "3" } {
           set smtpmailbcc $clienttcpdata
           set rec "4"
           log "BCC = $smtpmailbcc"
        }
    } elseif {$clienttcpdata == "DATA"} {
        set smtpdata $clienttcpdata
        log "data = $smtpdata"
    } elseif { $clienttcpdata != "." || $clienttcpdata != "QUIT"} {
           append smtpdata $clienttcpdata
           if {$clienttcpdata contains "Sensitivity: Company-Confidential\r\n" } {
               log "encript" }
           log "DATA = $smtpdata"
           log "Client data = $clienttcpdata"
    } elseif { $clienttcpdata == "." } {
           log "end of data" 
    } elseif { $clienttcpdata == "QUIT" } {
           log "QUIT"
    }
 
}