All About Email Appends

A data append is when data is added to your database or data file. An email address append is when an email address is added to a database record when the email address data field didn’t exist before. Why would anyone want to append email address data to a data record?

The short answer to that is because you want to send an email and you can’t do that if there isn’t an email address to send to. There are many reasons why you wouldn’t have an email address for every record:

  • Manual database input human error
  • Point of sale (POS) system creates records in your database without an email address
  • Person submitting a form enters in malformed email address or erroneous email address to be able to submit a form
  • Data entry forms don’t collect an email address data field or if they do, the field is not required to submit the form

Email Append Next Steps

You can have a data provider match your database records to their database of email addresses and append an email address to your data file.

Not all data providers are created equal in terms of “match rate” (matching a valid email address), and you may have heard conflicting sources about best practices on sending to the newly appended email addresses. And contrary to what some data providers try to sell you, there is no such thing as pre-opt-in email addresses. Opt-in email addresses are email addresses that took an action to agree to receive emails from a specific sender. Any email addresses appended to your data file are not pre-opted into receiving email from you.

What is almost always the case is that data providers append email addresses created in a “free” email platform like Gmail, Hotmail/MSN/Live, AOL, etc.. Basically, “free” really means that they use your data as payment for being able to use their email service. If you don’t believe me, be sure to read the Privacy Policy next time you’re logged into your email account.

Here is how it works:

  1. You supply a file of your records to a data company
  2. They run the file and match records to their database of email addresses
  3. They append an email address to your file when there is a match
  4. The data company deploys emails to your email appended list on your behalf from their domain/IP address(es)/ESP that drive subscribers to your landing page or your website, where they respond to your call-to-action, and that’s when you collect consent to send them emails directly from you in the future
  5. You may continue to have the data company deploy emails to non-responders, and then supply the data company an ongoing responder file for suppression (so customers don’t continue to receive offers)

A reputable data provider would never, ever give you access to the appended email addresses. If they do, run—run as fast as you can. To that point, never deploy emails to acquired email addresses from your email platform, if you value your sender reputation (even if they are your customers and you own their postal mailing data). The only next step we recommend is to have the data provider deploy a campaign on your behalf to the list of appended email addresses from their email platform.

Special Concerns

You can’t send an email to Canadian or European email addresses (and other countries) without prior consent, therefore scrub any records off your file(s) prior to supplying the information required to append an email address to a data provider.


Expectation setting is the trickiest part of any email append or list acquisition in terms of performance. Obviously, we all hope for the best engagement, responses galore and increased sales, but it is always best to be cautiously optimistic.

Conversions are a success metric you care about the most, right? That is the net of using a reputable data company for the appends. You want a company that has a solid email platform and a great sender score/reputation in order to give you the best shot at reaching an inbox. From there, you want to be sure you have strong incentive for opening the email in the “From Name” and “Subject Line,” and a convincing content/offer that motivates the click-through.

In terms of what to expect as a “Conversation Rate,” it depends on the perceived value of the offer.

For “Total Open Rates” you can expect anywhere from 0.5%–4.0% when sending to email addresses that haven’t opted in to receive email from you. That is true for both email appends and full list acquisition, though email appends perform better typically because there is already brand awareness and a business relationship.

What can go wrong?

Like any email campaign, recipient behavior in terms of spam complaints and unsubscribes can be minimized by following email best practices. Regardless, some dissatisfaction is unavoidable, and how those recipient actions contribute to ISP actions (like Blocking and Blacklisting) are out of your control, the agency’s control and the data provider’s control.

You may have started off with a good-sized list. The more campaigns sent to non-responders, the higher the chances that blocks will eventually creep up. I have seen it where blocks result from the very first send, resulting in the second send being deployed to only 50% of the list. I have seen it where campaigns continued monthly more than 6 months before any ISP’s blocked the Sender Email domain and sending IP address.

Blocks and Blacklists aren’t the end of the world, but they do take time to resolve. Think of it like your credit score. If there is a negative event, it takes time to build back up your credit. The same holds true for email-sender reputation.

Generally speaking, there are less issues when all rules are followed in Q1 and Q2. Halfway through Q3, ISPs start making their inbox algorithms more restrictive for increasing email volumes hitting their servers. By Q4, I advise most organizations interested in sending email to appended emails or acquired lists hold off, or at the very least keep hopes up and expectations low.

data appendemail address appendemail marketing

Jenny Lassi • March 28, 2018

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