February 18th, 2020 | by

Have you ever crafted an email sequence you were really excited about … and watched in disappointment as less-than-awesome results rolled in?

High email bounce rates are a campaign killer, no matter how great your content is.

We’ve all been there.

We’ve bought lead lists and tested them. We’ve seen lists with a 40% bounce rate (yes, really), and many others around 15% … but few people in sales and marketing rely on lists alone.

The reality is that most sales and marketing automation tools and CRMs use data from a variety of sources: usually a combination of (1) purchased third-party data, (2) user-generated data from form-fills, and (3) information that is manually entered in-house.

what is email spam

Our squeaky-clean data is in a league of its own, but we wanted to see how it stacked up in real life, which can be hard to quantify.

Our partners at Tellwise were able to take a peek under the hood of their tool and give us insight on email accuracy from real campaigns, which can be hard to quantify.

Tellwise’s smart messaging tool – which integrates directly with ZoomInfo – tracks emails to give sales reps with insight into open rates and engagement with attachments, as well as the ability to see when that activity is happening, in real-time.

From there, sales reps can instantly call or IM the prospect to answer questions and deepen the relationship.

Read It: What’s the difference between cold email and SPAM?

A real look at email bounce rates

Tellwise ran some numbers to see what happens when their customers send general campaigns.

This data tells us what usual bounce rates are for sales professionals sending one-off emails through tools like Tellwise. But the real value came when they looked at what happened to only the emails directed towards contacts that currently exist in ZoomInfo.

Let’s just say the results were staggering.

We looked at days where Tellwise customers sent 1000 or more emails to contacts in ZoomInfo, between Dec 18th, 2017 and January 7th, 2018.

Here’s what we found:

cold email good data

Over this period in late 2017 and early 2018, emails to ZoomInfo contacts through Tellwise bounced 1.47% of the time. Emails to the entire Tellwise universe of contacts bounced at a 5.38% of the time. (Average bounce rates, according to Smart Insights, are between 6% and 12%.)

Read the case study pitting ZoomInfo against a major competitor, which found:

  • The competitor’s bounce rate was 5x higher than ZoomInfo’s
  • ZoomInfo’s open rate was more than 2x higher
  • ZoomInfo’s positive response rate was over 4x higher over all 8 touches

How is this possible?

Are emails in ZoomInfo really over 3.5 times cleaner than the typical email address used by sales professionals?

The short answer is “Yes!”

The 1.47% bounce rate for emails to ZoomInfo contacts includes multiple emails, which is not to say that ZoomInfo’s emails bounce at a 1.47% rate across the board. (When Tellwise users communicate with prospects several times on the same day, the percentage of emails that bounce decreases.)

Get the free Ebook: What the @#$% Happened to Email Deliverability?!

A woman initiates a cold email campaignThe overall data includes data from ZoomInfo. Because Tellwise integrates directly with ZoomInfo, Tellwise users get cleaner data than the typical sales professional. So the numbers for the “overall” statistics are likely generous, given that there’s a disproportionately high percentage of ZoomInfo contacts in there.

Tellwise CEO Conrad Bayer says: “The quality of data is a significant factor in the productivity of our customers sales reps.  A sales role is difficult enough without having to waste time trying to communicate with people that are no longer there.  It is a time a moral killer.  When they work with ZoomInfo, data quality goes from being a challenge to a strategic asset for them.”


It’s also important to note that these numbers do not reflect an astronomical sample size (65,000 emails sent over a five-day period), so the data is prone to being more heavily influenced by a few individual Tellwise customers and/or their specific campaigns than we would have liked.

The rest of the data for days with less than 1,000 emails to ZoomInfo contacts actually indicate that the bounce rate may be a bit conservative, and the gap between overall bounce rate and ZoomInfo data is likely higher.

Read it: 8 Brilliant Basho Cold Email Examples for Sales Outreach

How is data quality accomplished?

ZoomInfo has been providing B2B contact information since 2007, and throughout the years we’ve gotten pretty good at figuring out what it takes to keep a database clean:

  • Data management is easy with Append & CleanInnovation and investment: ZoomInfo pumps over $15 million into our proprietary data gathering and cleansing process every year, with the sole purpose of providing our customers with quality data.
  • Strategic partnerships: We have partnerships with multiple services and proprietary data feeds, in addition to Tellwise, to notify us whenever emails to contacts in our database bounce.
  • Data integrity: Our Research Operations team at ZoomInfo is responsible for monitoring the health of the email addresses in our database. We have several daily reports that track the percentage of invalid emails in a random cross-sections of our database – and a host of other tracking methods.

#discoverorgsuccess discoverorg reviewsWhen emails in ZoomInfo bounce, we have the industry’s largest research team following up on that data to ensure that ZoomInfo continues to provide the most accurate data in the business; for example, when we are unable to validate a contact’s email through our other tools, we have a researcher call their company and confirm their email.

These are just a few of the reasons why emailing contacts in ZoomInfo results in least 3.5x fewer bounces than the typical B2B sales email campaign.

Incorrect, outdated emails cause problems that go a lot farther than that sinking feeling you get when a great email campaign fails: your domain reputation suffers and can even be blacklisted.

It’s faster and cheaper to prioritize data accuracy in the first place.


How much is bad lead data costing you? What’s it worth to fix it?



Cheer up. Check out the industry’s most reliable B2B contact data.


Derek Smith
About the author

Derek Smith

Derek was DiscoverOrg’s first researcher in 2007 and now a decade later he’s responsible for the processes and technologies that DiscoverOrg’s research team uses to create and update the data in our industry-leading sales intelligence platform.