IP score and IP reputation

When it comes to send mass emails, it’s always necessary to put the greatest attention to your IP score or IP reputation.

In fact, the ability of your newsletter to reach your recipients’ inboxes – that is, deliverability – depends not only on “internal” factors such as a proper HTML structure, good images and a subject line that doesn’t contain spam-risky words. On the contrary, it relies heavily on the reputation of the Internet Protocol (IP) from which you’re sending the messages.

Technically, an IP is a number that uniquely identifies a device connected to the Internet, and appears in the source code of every sent or received emails.

If you send unsolicited messages, get spam complaints and mail out to nonexistent addresses (provoking hard bounces), the IP score or reputation will consequently decrease. Which means that it will be subject to more restrictions by spam filters – or even wind up on a blacklist – affecting drastically your delivery rate.

A good way to check your IP score is to use the tools provided by SenderScore, SenderBase and others:


The main problem with common email providers is that they rely on shared and uncontrolled IPs, so even if you send perfectly legitimate emails your protocol can be used by a heavy spammer – and you will pay the price in terms of blocked messages.

Luckily, you can solve this issue once for all switching to a professional SMTP service like turboSMTP, which for a very small and flexible fee will provide you only reliable IPs – never blacklisted and never shared with shady senders. Eliminating the risk of winding up as a spammer, and making your emails get to the inbox.