Increasing and Maintaining Sender Reputation

We have written many blog posts about email strategy and deliverability advice to enhance your email marketing campaigns and develop your reputation as an email sender. But, what exactly is a sender reputation and why is it important to your email marketing? We’ve got you covered. This post is all about email sender reputation, as well as Inboxroad’s role in our customers’ sender scores.

What is a sender reputation?

One crucial step to email deliverability is ensuring that you have a positive sender reputation. A sender reputation determines whether or not your emails reach your subscribers’ inboxes. Internet Service Providers (ISPs) assign a score to each company or organization that determines their email sender reputation.

A high score tells ISPs that the sender is reliable and trustworthy, whilst a low score suggests that a sender might be spamming their email users. Internet Service Providers are interested in the concerns of their email users. Therefore, they use sender reputation to assess whether an email deserves to end up in an inbox, spam folder or become blocked.

What happens if I have a low sender reputation score?

Having a low sender reputation might lead ISPs to send your emails to spam folders or reject their delivery completely. If your reputation is consistently low, your domain or IP might even be blacklisted.

What determines a sender’s reputation score?

A sender’s reputation score is determined by several things:

  • The number of emails sent by the sender
  • The amount of emails by the sender that were marked for spam or that received complaints
  • The frequency that a sender’s emails lands in a spam trap
  • Whether the sender is blacklisted
  • A sender’s email bounce rates
  • Open rates, click rates, replies, forwards and deletions of a sender’s messages
  • The number of people that unsubscribe from the sender’s email lists


Various internet service providers may have different ways of measuring a sender reputation score. Some ISPs might focus more on the frequency of landing in spam traps or on the amount of people that unsubscribe from a sender’s list. A key point to highlight is that a sender with different domain names and IP addresses will be assigned separate sender reputation scores according to the various IPs and domains.

How to improve and increase your sender reputation

There are several best practices that you can implement as an email marketer to maintain a positive sender reputation. One essential best practice to implement is maintaining good email list hygiene. In this post, we provide insight into list hygiene and segmentation. Essentially, ensuring good list hygiene can lead to less email bounces. Alongside list hygiene, ethically promoting subscription to your email lists is important. Offer easy sign-ups and motives to join your email list, rather than unethically buying contact lists.

It is also beneficial to keep track of your email delivery rates. Keeping an eye out for bounce rates, click rates and overall engagement you will remain one step ahead of your sender reputation.

Composing engaging emails is another significant step to increasing your sender reputation. Making sure that your emails have a lot of interaction will convince ISPs of your validity and reliability as a sender.

Finally, IP warming is crucial to your sender reputation because sending out emails with a ‘cold IP’ is a sure way of negatively impacting your reputation and ISPs perception of you. Luckily, we have a post dedicated to IP warming.

Inboxroad and your Sender Reputation

Where does Inboxroad play a role in all of this? Our team uses monitoring tools, such as Postmastery, to keep an eye on our customers’ sender reputations. We personally communicate with our customers to explain to them the steps they need to take to improve their sender scores. Generally, a score above 80 is considered a good sender reputation.

Additionally, we check our customers’ reputation measures. For example, a customer being blacklisted, receiving complaints, facing bad DNS settings, sending out spam messages, sending to spam traps or sending messages to unknown users are all reputation measures. Inboxroad monitors customer reputation measures and subsequently offers recommendations to see our customers succeed. Finally, Inboxroad also monitors blacklisting and we request a delisting when a domain or IP becomes blacklisted.

If you are interested in knowing more about Inboxroad, please feel free to contact us!