Security causing mail problems

Cannot reply, forward or send attachments. Have worked on this for 2 days
within the Windows Mail Forum. Something is causing a delay in getting mail
to the server. This appears to have something to do with security. Has anyone
seen a resolution?

Details -
Unable to send mail problem was sporadic. Had Norton 2007. Took it in to
tech support for service and they upgraded to 2008. At forum suggestion,
deleted Norton and used the symantec utility to remove the remaining pieces.
Replaced Norton with CA Suite. One person thought the Norton proxy may not be
able to be removed.
My ISP is RoadRunner high speed over cable. Have checked all setting w/RR.
Inbound, outbound servers work. RR does not cross over servers nor do they
block any ports. I am able to send anything through their webmail with no
problem.
Error:
Your server has unexpectedly terminated the connection. Possible causes for
this include server problems, network problems, or a long period of
inactivity. Subject 'Re: Email issues?', Account: 'pop-server.stny.rr.com',
Server: 'smtp-server.stny.rr.com', Protocol: SMTP, Port: 25, Secure(SSL): No,
Error Number: 0x800CCC0F

If no security fix is known, any others ideas where to look for solution?
Do I need to do a system restore from my disks?