What is a seed list and how does it improve email deliverability?

Avatar for Leana Yang Leana Yang
Avatar for Leana Yang Leana Yang

June 19, 2024

2 min read

What is a seed list and how does it improve email deliverability?

What is a seed list?

A seed list is a monitored set of email addresses that helps you track your inbox placement. If you’re wondering why bulk emails have been landing in the spam folder, you should conduct a seed list test.

How does a seed list impact email deliverability?

Regular seed list testing helps improve email deliverability by giving you insights into how you’re inboxing. Monitoring your deliverability levels through this process will allow you to react quickly to any changes you observe within your inbox placement levels of the monitored ISPs in your tests. Improve your domain reputation by ensuring that you are properly authenticated, and by monitoring blacklist activity.

Sign up for our free trial of our Deliverability tool to see if your email contains and passes SPF, DKIM, and DMARC.

How do I create a seed list?

The fastest and easiest way to create a seed list is to choose an email deliverability service that offers it. From there, you'll need to place that seed list into the CRM of your choice like HubSpot, ActiveCampaign, or MailChimp.

Choosing the right email deliverability provider can be quite daunting. Many offer advanced options with features that you likely won’t need for a premium price.

Here’s what you should look for when choosing the right provider:

  1. Quick and easy seed list implementation
  2. Good variety of emails within the seed list
  3. Easy to visualize and action metrics
  4. Self-serve vs dedicated managed services
  5. The ability to also verify and validate emails

Here a list of the best email deliverability tools:

5 = Best, 1 = Worst

Fastest Setup Time Ease of Use Seed List Quality Platform UX Managed Services Email Verification
Emailable 5/5 5/5 4/5 5/5 ✔️ ✔️
Glock Apps 2/5 2/5 1/5 1/5
MailMonitor 2/5 4/5 2.5/5 2.5/5 ✔️
Everest 5/5 5/5 5/5 3/5 ✔️ ✔️
ZeroBounce 3/5 1/5 3/5 3/5 ✔️
InboxMonster 4/5 5/5 5/5 4/5 ✔️

What do your results mean?

Seed lists are comprised of multiple email addresses within the major ISPs in our industry (Gmail, AOL, Yahoo, Outlook, Office 365, etc.). After a campaign is sent to this list, you will be able to examine the percentages of placement for these results for each ESP (Email Service Provider).

Seed test results are essentially divided into 3 categories:

  1. Inbox Placement Percentage - This category represents the percentage of our seed list (broken by each specific ISP) that was filtered into the inbox when received from your sending domain/IP address
  2. Spam Folder Percentage - This category represents the percentage of our seed list that was filtered as either junk or spam when received from your sending domain/IP address
  3. Missing Percentage - In instances where you send to our seed list, and the message is not received (bounces, blacklistings, blocks, etc.), you will receive a missing percentage.

These results allow you to gather the perceived reputation of your sending domain/IP address. If you are seeing strong inbox placement through your results (80% and above), this is an indicator that these tested ISPs are likely not taking any deliberate action to filter your email into the spam folders of your subscriber list.

High spam folder placement results are potential reputation issues for those specific domains. In these cases, we are likely seeing high levels of spam folder placement for the subscribers within your list that belong within that ISP.

Missing percentages are typically caused by a bounced email due to spammy content or due to an ISP block.

How often should you test?

If you send bulk emails regularly, you should be testing consistently. Scheduling tests will allow you to have the most visibility into potential changes in your sending reputation.

At a minimum, you should test weekly. However, sending tests before and after significant email campaigns will allow you to track reputation levels before and after these campaigns are sent.


Discover why the world’s largest companies choose us to improve email deliverability

Start Free Trial