If the virus check of your security software covers your mailer, the security software refers the incoming mail server as 127.0.0.1 in order to check for viruses, and may have an account name such as “Asahi Net ID/pop.asahi-net.or.jp” when it is actually accessing the server.
Usually there should be no problem, but a bug (e.g., not able to connect to the mail server) may occur when some kind of error happens in your mailer or Norton AntiVirus.
If you are using a security software, please check your settings.