Error msg is "The TCP/IP protocol stack reported that it ran out of memory. Consult your network documentation to increase configured memory, or reduce Notes connections by limiting clients (See SERVER_MAXSESSIONS parameter in Notes Admin Guide).
Subject: TCP/IP error…
My experience is that is what it sounds like. Restarting Domino may fix you up (at least for the moment). If this is not a one time occurrence, you will have to find out what is chewing up the memory. Have you recently changed your backup or virusscan software?