ERROR WHILE CREATING THE SALES ORDER

Hi,

After creating the sales order and while trying to save it im getting a message saying "Express document "update was terminated"" recieved from the author "Rahul".

When i check the inbox, it says "definately cannot transfer message to node SMTP due to connection error".

This is hapenning for only one user.

What could be the problem?

Regards,

Rahul.