Every email user receives unsolicited e-messages they’d rather not see. Whether these come from spammers or fraudsters, they can be a nuisance. Luckily, there is a way to keep malicious parties at bay. IPs involved in questionable activities are included in dedicated blacklists. Here is how these anti-spam defenses function.
Internet Service Providers (ISPs) use the lists to weed out spammers. With specialized websites, it is now easy to report any IP address via report IP services. Every complaint boosts the efficiency of email filtering across the web. On the other hand, if you are the sender of large volumes (e.g., as part of a digital promotion effort), it is crucial to check that your IP location is not classified as fishy.
How the Systems Work
IP addresses and domains associated with active mailing are closely monitored by Mail Abuse Prevention Systems and other entities. The resulting databases of dubious senders are constantly updated. These are, in turn, used by ISPs for anti-spam defense. But how does the detection work?
Here is what happens when you send an email. First, the system logs your IP address. The data enables the mail servers of the recipients to verify the sender. They connect to databases to ensure you have not sent suspicious messages in the past. For example, the CleanTalk blacklist now contains over 4.5 million IPs, 12.5 million emails and roughly 1.5 million sites.
If this check returns a match, your message gets automatically redirected to the junk folder — without scans of its content. What’s worse, if the IP/domain has been involved in repetitive violations, the message will be rejected, not even landing in the junk.
When It Usually Happens
IPs may appear on the black databases as a consequence of automatic detection or user complaints (over the 0.01% rate). Things like spamming software or open relay servers are obvious cases for the former. Here are the most common grounds for user reports. A recipient is likely to dislike your messages if:
— they did not sign up for the mailshot;
— they failed to find the unsubscribe link;
— they forgot they opted in;
— they receive too many messages;
— the content is not what they expected.
Sometimes, inactive email addresses are turned into so-called “spam traps”, so you should keep your list updated.
How to Report a Suspicious Sender
Various websites, such as cleantalk.org, collect reports from users. All you need to do is enter the IP or email address and specify the type of attack. Include comments if necessary, and leave basic contact information if you would like to receive a response. At the same time, it is possible to check if a specific IP or address has been blacklisted.