(FAQ) How can I prevent Winsock error 10053?

Winsock error 10053 seems to be occuring on SMTP mail to and from MDaemon.

Winsock error 10053 usually occurs with routers, firewalls and proxies. Are you using any of these? If you're using a router, please be sure that the MTU setting is at 1500. Then, see if this resolves your issue. If not, double check the MTU setting on the MDaemon server (the MTU setting is in the registry).

Here's more on Winsock 10053:

WSAECONNABORTED (10053) Software caused connection abort

A connection abort was caused internal to your host machine. The software caused a connection abort because there is no space on the socket's queue and the socket cannot receive further connections.

WinSock description: The error can occur when the local network system aborts a connection. This would occur if WinSock aborts an established connection after data retransmission fails (receiver never acknowledges data sent on a datastream socket).

TCP/IP scenario: A connection will timeout if the local system doesn't receive an (ACK)nowledgement for data sent. It would also timeout if a (FIN)ish TCP packet is not ACK'd (and even if the FIN is ACK'd, it will eventually timeout if a FIN is not returned).