Since reputation systems became the primary method of spam filtering, the focus has been more on IP address reputation and less on domain reputation. Now, IP address reputation is less important for inbox placement than domain reputation and message content.
With the advent of IPv6, every electronic device in the world can have its own IP address. Because so many IP addresses are available, spammers can afford to waste them. ISPs cannot rely only on blocking IP addresses to protect their networks. IPv4 is still the default for email but that is changing, and spam filters are adapting.
Technology improvements progressed from simple IP reputation engines to ISPs and filter vendors that collect more metrics about email than ever before. Technologies like DKIM, SPF, and DMARC now make it possible to trust more data. Trusted data is used for reputation decisions and spam filtering.
What to focus on
IP reputation is still critically important but is focused on the moment when the email is offered for delivery. When the mail is accepted, the rest of the reputational blend is used to determine whether the email is placed in the inbox or the spam folder. The reputational blend includes domain reputation, content (including links and images), and customer interaction with the email.
Today, email marketers should focus on engagement at least as much as on IP address reputation. Authentication must be in place and correct. When that is done, focus on creating and maintaining a well-segmented database and an interested, engaged audience that interacts positively with marketing email. The more effective the email that is delivered, the better deliverability gets.
Diagnostic tools and IP checkers
Network and forensic tools
For more information, see the following websites:
- DNS checking tools (web-based interface)
- Dmarcian
- Free online network tools (no login required)
Some ISPs offer more in-depth information about what happens to marketing mail after it is in their systems. Proof of ownership is required in some form by all of these sites.
- Hotmail SNDS provides traffic data, such as mail volume, complaint rates, number of spam traps hit, and filter status. For more information on setting up a Microsoft Hotmail and Outlook SNDS interface, see Set up Microsoft SNDS.
- Google Postmaster Tools provides some data about complaint volumes and reputation. For more information on setting up Google postmaster, see Set up Google postmaster.
- QQ.com (Tencent) (in Chinese) provides data about messages that are sent, messages received in the inbox, filtered messages, read rate, and complaint rate.
- Yandrex.ru (in Russian) requires a login. Currently, we have no information about this offering.
- mail.ru (in Russian and English) provides data about complaint volume, percent delivered/blocked/spam-foldered, messages read, messages that are deleted after being read, and messages deleted unread.
ISP Postmaster pages
For more information, see the following websites:
- AOL
- AT&T
- Charter (now XFinity)
- COX
- Frontier
- Free.fr
- GMX
- Hotmail
- Mail.com
- Time Warner (Road Runner)
- Yahoo
IP address and domain name reputation websites
For more information, see the following websites:
- Cisco Lookup SenderBase allows you to look up your email and web reputation.
- Return Path SenderScore provides a comprehensive reputation measurement.
- Proofpoint Dynamic Reputation provides information about your IP address.
- SophosLabs IP Address Classification Lookup provides information about your IP address.
- Spamhaus provides an IP address Lookup Tool.
- Symantec IP Address Reputation Investigation allows you to request an investigation into a negative reputation.
- Time Warner Cable Block Lookup allows you to check whether your IP address is being blocked.