In Terminal.app, I did a host smtp.eigbox.net which yielded smtp.eigbox.net has address 38.113.1.135. I also did a host 38.113.1.135 which yielded 135.1.113.38.in-addr.arpa domain name pointer ip38-113-1-135.yourhostingaccount.com. I also did a whois 38.113.1.135 which yielded a PSINet, Inc. COGENT-NB-0002 (NET-38-112-0-0-1). Does yourhostingaccount.com or PSINet mean anything to you?