A client of ours has 2 Exchange servers, one in each office. After resolving a problem for them within exchange I noticed the message queues for both servers have a number of strange entries which all have a status of "The remote server did not respond to a connection attempt"
Strangely after speaking to the client, they have not been trying to send email to any of these domains, and i'm afraid that somehow the server, or a client has a virus of some sort.
Upon opening the messages in the message queue, the sender is postmaster@..emaildomain.com
Below is a list of the domains.