I have an issue where my employees cannot send to a particular external domain. They receive an email from us on a rare occasion, but others never make it and we don't get any NDR or delay messages. I've tried doing read and delivery requests, but you can't expect much of those. I'm not having this with any other domain. The external domain says that they have added our domain to be safe and have added the IP address of our sending server. Neither party is on any blacklists. The attempted recipient states that they don't see any evidence within their AV (I think they said McAfee). Anyhow, I'm wondering if anyone knows of a site/tool that will allow me to track my outgoing emails? As I have to trust that the recipient's IT dept know what they are doing, I'm hoping to collect as much info as I can.