The feature, designed to intercept malicious e-mail messages before they land in the user's inbox, is causing confusion amongst users and angering ISPs, according to computer troubleshooting Web site BugNet.
Norton Antivirus versions 7.0 and above contain a program called Poproxy. This program sits in between the user's e-mail client and the mail server run by the Internet service provider (ISP). Incoming e-mail is routed through Poproxy for a security scan.
When Poproxy fails to run -- perhaps because of a conflict with another system process -- users get an error message saying: "The connection to the server has failed." When Norton Antivirus is installed the e-mail client preferences are changed to connect to Poproxy instead of the service offered by the ISP.
Symantec admits customers have reported e-mail trouble, but the company does not regard this as a product flaw.
"Usually it is a configuration error or installation trouble, nothing that can't be resolved," said Chris van der Grift, consumer product lead of Norton products at Symantec EMEA.
Van der Grift has no information on programs causing conflicts with Poproxy, but said there has been another cause blocking access to e-mail: unknowing users incorrectly disable the Poproxy program because they don't trust it.
"Overcautious customers tend to disable Poproxy manually in the Task Manager (accessed by hitting Control-Alt-Delete in Windows), others get weary of the program and decide to block it when their personal firewall reports that Poproxy is trying to connect to the Internet," said Van der Grift. "They don't realise that Poproxy is part of Norton Antivirus."
Resetting the preferences in the e-mail client to the ISPs mail server will fix the problem, but will disable protection by Poproxy. However, according to Van der Grift, the system is still secure with Norton Auto-Protect enabled. This feature scans all files before they are run.