We have recently switched to Trend Micro Hosted Email Security for our inbound and outbound mail filter. And we now cannot send email to AT&T.net. They have much better email security than we did in house, so I don't understand why it is being blocked. the current outbound IP is 18.104.22.168, however, there is no guarantee that will stay the same forever. It would be nice if you could work with Trend Micro to prevent any further issues, you are both pretty big companies, it seems reasonable. But at the very least could you delist this IP address for me?