The Perks of Being a Reputable Sender
As more mailbox providers move to machine learning algorithms, and these continue to get smarter over time, staying reputable with mailbox providers becomes more important to keeping your marketing content in people’s inboxes.
Your reputation is how a mailbox provider views your mail, and roughly 79% of bounces we see are due to reputation. Each mailbox provider uses a different reputation algorithm, however the core principles behind each is the same. The more positive your reputation, the better your inbox placement, so knowing how to build good reputation is crucial.
This is especially important for media and publishing companies, where email is often a high frequency channel. Daily newsletters, breaking news alerts, promotional sends, and multiple publications or brands can create significant sending volume. Maintaining a strong reputation helps ensure those messages continue reaching the audiences that rely on them.
I’m a B2B Sender, Does This Affect Me?
B2B reputation functions slightly differently than B2C reputation, generally relying more on mail content, spam trap hits and spam complaints.
By keeping complaints low, you’re letting mailbox providers know that your mail is wanted. And keeping complaints low is a combination of sending the right email to the right people at the right time.
There are several ways you can do this. A/B testing and personalisation helps create the outcome-driven email that successful B2B senders rely on, and Personalised Delivery Time allows recipients to receive mail when they’re most likely to open it.
For more information on spam traps see our previous article. We’ll have a deeper dive into B2B deliverability in a future article.
Positive and Negative Reputation Signals
Everything a recipient does with a mail influences your sender reputation, but it’s not just recipient behaviour. Below you can find some examples of the common signals mailbox providers use to determine reputation.
Positive reputational signals
- Full authentication (Ensure mails are passing SPF, DKIM, and DMARC. Your ESP usually handles this)
- Low bounce rates
- Opens and clicks
- Marking mail in spam as “Not spam”
Negative reputational signals
- Failing authentication
- Deletions without reading
- Marking mail as spam
What this boils down to is making sure your mail is set up correctly from an authentication standpoint, and sending recipients mail they’re likely to interact with.
For publishers, engagement can also vary significantly across newsletters and audiences. A subscriber who reads a daily news briefing every morning may interact very differently with a weekly newsletter or promotional email. Looking at engagement at the newsletter, audience, and brand level can help identify where reputation risk may be developing without unnecessarily reducing mail to your most engaged readers.
Checking Your Sender Reputation
While mailbox providers are looking to make reputation more opaque, with a bit of intuition you can work out where you stand. Each provider has their own methods, and there are multiple tools out there to help you.
| Google Postmaster Tools (GPT) | Google’s Postmaster Tools webpage has recently undergone a bit of a facelift. It’s Google’s one-stop hub to check your compliance with their sender guidelines. To see a domain on GPT you’ll need to prove you own it by adding a specific DNS record then if you’re sending more than a few hundred messages per day, you’ll see various compliance stats within the GPT dashboard. |
| Microsoft Smart Network Data Service (SNDS) | Unlike Google Postmaster Tools, SNDS looks at IP reputation instead of domain reputation. If you’re using a dedicated sending IP, your ESP should be able to grant you access to Microsoft’s SNDS. Here, you’ll be able to see your overall IP reputation on any specific day, along with your average complaint rate, sample complaints, and rough timings for any of Microsoft’s Spam Traps you’ve hit. |
| SenderScore | Validity’s SenderScore was once a very valuable tool and while it’s less relevant these days it’s still a useful data point. Validity aggregate data across a sensor network and assign a score based on the number of bounces, spam complaints, and trap hits they observe. A higher score here can indicate better trust with mailbox providers, but shouldn’t be your only data point. |
| Cisco Talos Intelligence | Talos is Cisco’s reputation centre for B2B mail. Cisco builds up reputation for the sender domains and IPs, but it also collects data on how reputable the website behind these domains is. If you see issues here, you may have trouble delivering to B2B inboxes. |
| Blocklist Checks | If you’re on an impactful blocklist, there’s a good chance that some of your sending practices can be improved. Using tools like MX Toolbox or other real-time blocklist checks will help you identify if you’re on any specific blocklists. While these may return multiple blocklists the major ones you actively needs to worry about are Barracuda, Proofpoint, and Spamhaus, as these have a very large impact on deliverability. |
Publishers with multiple brands, sending domains, or dedicated IPs should also avoid viewing reputation as a single company-wide metric. One publication, newsletter, or portion of your sending infrastructure can develop reputation problems while the rest of your program continues performing normally. Monitoring reputation at the appropriate domain and IP level can help you identify and address issues before they affect more of your email program.
Reputation as a Strategic Advantage
For media and publishing companies, sender reputation isn’t just a deliverability metric. It directly affects your ability to reach readers, drive traffic back to your content, promote paid subscriptions, and monetize your newsletter audience.
High-frequency sending, multiple newsletters, and complex audience segments make reputation something publishers need to manage continuously rather than only when inbox placement begins to decline. Prioritizing list quality, monitoring reputation, and understanding how different audiences engage with your email program can help protect both your inbox placement and the business outcomes email supports.
If you’re unsure where your sender reputation stands, PostUp’s deliverability team can help evaluate your sending domains, IP reputation, authentication, complaint rates, blocklist status, and mailbox-provider data to identify potential risks and opportunities for improvement.