Previously, only email sent from networks other than
SpinNet used the method known as "POP before SMTP."
In order to further increase security, we've implemented a policy
to ensure that all our email is now sent and received with this method.
"POP before SMTP" is a method in which a user authentication
is performed when an email message is transmitted. This system ensures
the email is sent only after the intended receiver has been authenticated.
SMTP servers (sending servers) cannot be protected against spam email
transmission and its reporting because they have no user authentication
function. Therefore, many cases of misuse have reported.
(Anti-spam measures: http://www.spinnet.jp/csc/fromcsc/040916e.html)
With the POP before SMTP method, the POP server (receiving
server) confirms the existence of the SpinNet user before the
email is sent. In this way, the sending of spam email to the
SpinNet mail server is prevented.
To accommodate the POP before SMTP method, you might have to change
the preference settings in your email software. If you cannot currently
send and receive email without difficulty, check the following settings
in your email software. If you are not having difficulty sending and
receiving email, there is no need to change your settings.
Note: If you still cannot send or receive email
...
For security reasons, the POP server authentication that takes place
before the email is sent becomes invalid after about 10 minutes. If
you do not transmit the email soon after authentication because you
are writing a lengthy email, or if the connection is broken, transmit
the authentication again to send the email.
Moreover, an increasing number of Internet service providers have
implemented "Outbound Port 25 Blocking" as a spam countermeasure.
In some cases, SpinNet customers who attempt to access their
email through such a provider cannot send email even with the POP
before SMTP settings. For more information, please visit the following
website.
