When it comes to email marketing, there is perhaps nothing more important than your ability to reach someone's inbox.

The chances of engaging with your audience decreases drastically if the email doesn’t reach the right places. Put simply, the more you hit the inbox, the more chance that someone will read and then engage with your content. We refer to this as deliverability, and there’s a multitude of different ways you can affect this. In this post, we’ll be looking at the reputation of the sending IP address.  

What is IP Address Reputation? 

To understand IP address reputation, we need to take a quick look at the technical side of sending an email. To send an email you need a mail server. The mail server will use an IP address to host the connection from the sending mail server. An email will only ever use one IP address, but it’s likely that most email marketing providers will have a few different IP addresses in use across their group of users. Some IP addresses will have a specific purpose, like only being used for one high volume sender, or a group of different users that use the same IP address.  

Each IP address has its own reputation attached to it, which is based on the expected volume that will be sent, and the quality of emails that are sent from it. This will be a score ranging from 0-100, with 0 being the worst, and 100 the best.  

Why is the reputation of an IP address important? 

IP reputation is a huge indicator of whether your email is going to make it through to the inbox or not. The higher the reputation, the more likely it is that your email will be front and centre in a recipient’s inbox. Recipient mail servers tend to take the reputation of the sender into account when receiving emails. A low sender score could cause a recipient mail server to filter the email into the spam mailbox, or reject it entirely. The higher the score, the more reputable the sender is seen to be, so the less likely it will be rejected for any reason.  

Typically, IP addresses with a score of above 80 will have high chances of reaching the inbox. If you’re curious to see the reputation of the IP address you’re sending from, get in touch! 

How can you influence IP reputation? 

Sender reputation is tied to good email practice. The usual types of good behaviour when it comes to email marketing are important to maintain a strong IP address reputation.  

Make sure you’re sending to clean lists. Lists that contain a lot of old contacts that are no longer in use will increase your undeliverable rates, which will damage the reputation of your sender reputation. These old email addresses could have been repurposed into a spam trap, which are used to catch out spammers that have purchased lists of contacts that haven’t opted in. Sending to a spam trap could cause an IP address to be blocklisted, so make sure that you’re regularly validating your contacts with a list cleaner service.  

The quality of your content is also extremely important. Most receiving mail servers will have email security that scans the content of the email for potentially spammy content, so it’s important to make sure you run a spam score check on your campaigns. The list of tactics that spammers use is seemingly endless, but some examples of content that might get flagged are: 

  • Subject lines in all capitals
  • Subject lines that reference competitions with a financial reward or gambling 
  • Heavy use of monetary values in the millions 
  • Sending emails that are image rather than text based 
  • Sending email addresses that haven’t been correctly authenticated 

Keeping the quality of content high and making sure you’re sending to the right contacts will help keep the reputation of the IP address high, and help you reach the inbox of your recipients. 

Should I have my own IP address? 

When sharing an IP address with other users not at your company, it would be tempting to want a separate IP address to protect yourself. There is always the danger that whoever you’re sharing your IP address with may send an email that may cause the reputation to dip. Aside from the additional costs of having a dedicated IP address, is it ever really worth it?  

A well-managed mail server infrastructure requires input from both the users and the email marketing vendor. The users obviously play a massive role in the reputation. The reputation is based on the quantity and quality of the emails that are sent by the users. For the vendor, managing the user base to make sure that the right users are on the right IP address is just as important. Getting ahead of potential threats that may cause the reputation to dip, and making sure that users are educated in best practice will help the reputation much more than just segmenting users entirely.  

It’s only really when you’re sending in the very high volumes in the millions of emails per year that you might want to consider a dedicated IP address. These types of senders will be able to keep an IP address warmed up for high volume, but the quantity of emails has the greater chance of maintaining a strong reputation. If you’re not sending that many, then you’re better off with a shared IP address.

Curious to find out more about the reputation of the IP address you’re sending from? Contact our Customer Experience Team.