The implementation of OP25B enhances the prevention measures of spam email

Asahi Net blocks port 25 to prevent spam email going through in order to provide a safe internet environment for our members.

By ISP companies blocking port 25, spreading of virus can be prevented and the number of spam email can be reduced in advance by not allowing unintended distribution of spam email.

Asahi Net asks our members to understand the blocking of port 25 which enhances the security. Thank you for your cooperation.

What is OP25B?

OP25B prevents a large amount of email being sent through your computer or server whether intended or not by virus infected user or spam email sender.

Most of spam email sent using Asahi Net’s connection services are sent directly to outgoing mail server through port 25.

Blocking of port 25 limits the distribution of email through port 25, preventing unauthorized email being sent.

Benefits to block Port 25

Prevents sending a large amount of email and from personal information leakage

If your computer is virus-infected or accessed illegally, your computer may be exploited to send a large volume of spam email without going through Asahi Net’s outgoing mail server.
Your personal information may be contained in such emails.

Such unintended distribution of large volumes of email and information leakage can be prevented by blocking port 25.

Servers covered by OP25B