Send Error

The following error appears when I attempt to send mail (outlook express 6 in Win 2000 pro)that contains more than just a few words. (a test e-mail with 2 words, sends just fine)I have no problem using the identical setup (same account)in Win 98 with oulook express6.Here is the Error:

Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Subject ‘test’,
Account: ‘incoming.verizon.net’,
Server: ‘outgoing.verizon.net’,
Protocol: SMTP,
Server Response: ‘421
out003.verizon.net Lost connection to [151.204.115.186]’, Port: 25,
Secure(SSL): No, Server Error: 421, Socket Error: 10053, Error Number: 0x800CCC0F