Generally this happens when you are using an Internet Service Provider and your SMTP server is set to cornell.edu. As a security precaution, the Cornell servers have SMTP access restricted to Cornell-originating IP addresses. Check your mail prior to sending any mail. I am a Cornell Cooperative Extension staff member located off-campus and do not know my NetID password. Off-campus Extension administration and association staff should contact the Extension Electronic Technology Group who can assist them in getting a new password if necessary.
Turnaround time is approximately one week.
See the CIT instructions explaining how to Set Up Eudora for Multiple Users .