How To Increase Sender Reputation and Email Deliverability

Email continues to play an important role in public relations. For effective pitching, sender reputation is key to the success of any campaign.

Messages directed to spam folders or anywhere besides an inbox are the worst nightmare for PR experts. What good is the message if it doesn’t reach the recipient? With a damaged sender score, this is what will happen to your email communication.

What is sender reputation

Sender reputation is evidence of how trustworthy a sender you are. The better the reputation, the better deliverability rate you will enjoy and vice-versa. Incoming mail servers check all your messages with advanced spam algorithms. So if you reach your recipient inbox, gathering opens and clicks, you increase your sender score. Being red-flagged as spam by recipients too often results in a drastic drop of your sender score followed by delivery issues.

Not achieving any media exposure thanks to a failed email communication strategy is surely the last thing you need. That’s why we’ve put together 8 proven solutions that help keep your deliverability in the neighborhood of 97-99%. Implement these tips for better email performance, especially if you’ve noticed a low or falling amount of responses and opens.

1. Email and domain authentication

Internet service providers (ISPs) such as Verizon and email service providers (ESPs) like Gmail or Outlook verify the ownership of all emails reaching users inboxes in order to effectively block spam. You can help them in evaluating your emails by authenticating the IP address of the email server through an SPF record added to your DNS (Domain Name System) settings.  

This is a crucial, top-priority step before sending any campaigns, especially when using email service providers like Prowly. Unless you want half or more of your messages to land in spam or permanently disappear, authenticate your domain. It’s very straightforward—your recipient’s server just needs to know that IPs you use for sending emails are officially declared to be used on your behalf.

In addition to SPF, you need to add a DKIM protocol to your DNS server. It’s a second reliable authentication solution that will mark you as a trustworthy sender that distributes only legitimate messages. With an encrypted signature that is added to the email header, you will assure mailbox providers that the message was distributed by you and wasn’t somehow manipulated in the process.

On top of both protocols, you can additionally install a DMARC security record, which will serve a strong shield against all illegal email activities, like phishing and scamming. Criminals won’t be able to impersonate your organization and send spam all over the Internet, which can result in a damaged brand reputation and your domain landing on blacklists. If your SPF, DKIM, and DMARC will be off, you will never build a sender reputation. We write more about the values of DMARC authentication in this article.

2. Don’t send too many emails when starting

When moving to a new email service provider like Prowly, you receive a shared IP that is used by a number of legitimate companies. Their well-performing email activities build a high IP reputation, increasing deliverability rates. In other words, inbox providers recognize our valuable email traffic and accept your messages as well.


If you start email activities on your own, with a brand new domain and publicly unknown IP, you need to warm up slowly, so email clients will see that you’re following email good practices. How? Distribute just a few emails per week at the very beginning. The growth of your email campaigns should look like an exponential graph – sending mass emails to thousands of recipients without a warmed-up IP will label you as spammer.

Email providers like Gmail or Outlook can reevaluate your sender score at any time and adjust it accordingly based on the usual metric. Still, starting small and gradually increasing the number of mails you send is still the best way to go.

3. Double opt-in

Seeking geometrical growth of email performance, you shouldn’t allow any accidental contacts to get inside your database. PR experts who collect subscribers of brand or company newsletters always ask them to confirm their email addresses in what’s called the double opt-in model. This requires new subscribers to verify that they do in fact want to be added to a mailing list by clicking an activation link sent to their email address. Once clicked, you can verify newcomers in the welcome email. Its open rate tends to be pretty high and only spam robots or uninterested readers don’t open it.

4. Keep your contacts database in good order

Double opt-in is just one way to maintain hygiene in your contacts database. Over time, email addresses become invalid and messages “bounce” due to address or server issues. In Prowly, we allow users to flexibly arrange recipient lists for all email campaigns with the help of smart suggestions.

Excluding blacklisted and unsubscribed contacts is obligatory. There is no point in targeting addresses that no longer exist or people who are not interested in your content any longer. Additionally, we recommend eliminating addresses that were bouncing frequently, as well as those who haven’t open or clicked any links in 10 recent emails from you. The better email performance you achieve, the better your sender score will become, returning more and more opens and clicks in future campaigns.

Don’t contact random media that have no reasonable connections with your messages. For example, pitching automotive journalists and influencers with a press release about the newly invented VR technology is not a good idea. It will always ricochet back at you, as with every single spam complaint requested from the recipient, inbox providers reevaluate your reputation. Buying contact lists from unverified sources, which come with no guarantee that the addresses are accurate or even exist, can inflate the issue and is rarely beneficial. Check our constantly updated Media Discovery database if you would like to reach more journalists or read a success story from one of our clients about How Prowly Helped a Social Campaign Land 150 Publications and Go Viral.

5. Spammy subject lines

Domain authentication and an optimized contacts database will not bring results if you destroy your sender score by using spammy words into subject lines. Try to avoid salesy terminology and stay consistent with the content inside the email. We wrote about techniques for crafting subject lines that boost open rates like crazy in a separate article here.

6. Text-to-images ratio & clean HTML code

Spam filters red-flag emails that consist of more images than text. Don’t let the form triumph over the message and keep the ratio somewhere near 60-70%. When creating HTML emails for newsletters, optimize the code as well. Keep the size small and CSS style repetitive in every layout element. Always remember to use responsive design to help journalists read your content on mobiles and cut all multimedia that doesn’t render properly during testing.

There is a saying inside the marketing industry that two strong CTA buttons is just one too many. While this may not be the case all the time, it still illustrates the truth that too many URLs can make the page too busy and distracting. They simply increase so-called decision fatigue among recipients. An unsubscribe link, on the other hand, is a must-have to maintain compliance with CAN-SPAM rules.

7. Whitelisting

Some email inboxes can still block your messages or don’t display all template elements, even for subscribers that are truly ready for content consumption. It sometimes happens for companies with a damaged sender score, which have just started applying techniques you’re reading right now. Consequently, don’t be afraid of asking readers to whitelist your domain, for example in an email following your welcome message. Your messages will be considered legitimate, go straight to their inboxes and your deliverability rate will go up along with your reputation.

8. Frequency and purpose

Set a schedule for your email activities. Build habits that will help you grow your open rates and clicks and never deliver too many at once. If recipients feel overloaded, even when subscribed they will label your messages as spam. Gather insights about how frequently you should connect by email. Don’t merge emails with different purposes into one, keep them focused on a single idea. Transactional emails should be sent separately from marketing materials.

There are lots of ways to build and maintain a strong sender reputation. If you haven’t created SPF, DKIM and DMARC records in your DNS settings, you should definitely start there. Optimizing your database is another trick for achieving better email performance, but improving your sender score with spammy subject lines or suspicious content will never be possible.

You can also put the brand or organization name into the From name, like “Dominik from Prowly”. This builds credibility by maintaining a consistent From address and Reply-to address throughout all your campaigns.