Rakuten Broadband Premium

Standard SPAM Filtering Service

A standard (and free) feature of the Rakuten Broadband Premium mail system available to all Rakuten Broadband Premium customers. Users may configure the filters to their liking including such criteria as language encoding, local blacklists, and public real-time blacklists. No registration is required and changes can be made from the Member's Station.

Advanced SPAM Filter Service

Rakuten Broadband Premium also provides an additional, more complex SPAM filtering service for those customers who, despite using the standard filtering service, continue to receive sizeable amounts of SPAM. For a small monthly fee and a one-time registration, customers gain access to our implementation of a well-received tool called "SPAM Assassin." Customers can freely adjust the level of restriction to meet individual requirements. A complete overview and instructions for use can be found on the official service page.

Greylist

The Greylist filter is intended as a powerful "last wall" of defense against cleverly designed SPAM that sneaks by other filters. Incoming E-mail that seems suspicious is put into a temporary holding queue. Such E-mail will be stored on the server (24 hours maximum) awaiting confirmation from the sender's remote E-mail server. If the E-mail is confirmed legitimate within that time, an entry will be added to the Whitelist (to ensure that all future mail from that sender will be let through unobstructed) and then delivered to your inbox. What this means is that E-mail that is caught by the Greylist filter may be delayed in reaching your inbox by a few hours but this occurs only once and the sender will not be aware that any delay has occurred.

SES (Signed Envelope Sender)

NDN (Non-Delivery Notification) is E-mail that is returned to the sender due to undeliverability. Non-Delivery Notifications (also known as "bounces" ) that appear in your inbox due to remote mail systems incorrectly interpreting (and returning) undeliverable mail are known as "backscatter". The SES authenticity routine checks all such incoming mails for a Rakuten Broadband Premium-specific "signature" (which is inserted into all outgoing E-mail sent though the Rakuten Broadband Premium SMTP server) to judge whether or not the mail actually originated from your account. Only E-mail with a confirmed signature is allowed in.