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Email validation: Why you want quality versus quantity

Email communication has been around for decades, yet, it remains one of the most popular customer communication channels for marketing organizations. According to WordStream, 80 percent of retail professionals indicate email marketing is their greatest driver of customer retention, and 73 percent of millennials identify email as their preferred means of business communication.

Today, legitimate email campaigns compete with billions of spam emails sent out daily. To ensure successful delivery, reduce the chances of being filtered out by an email service provider (ESP), and avoid becoming blacklisted as a spammer, organizations need to ensure the accuracy of the email data held in their mailing lists. Of course, marketers want to reach as much of their target audience as possible, but when it comes to email address validity, it’s important to err on the side of quality versus quantity.

Savvy marketers avoid taking risks with email marketing because the consequences can be disastrous. Sending mass campaigns before email addresses are fully validated can result in lost potential sales, and in the worst-case scenario, retail brands could even be blacklisted before the revenue-driving holiday season. If an address cannot be fully validated, it’s prudent to put it aside until the circumstances change or you can reconnect with the customer to get an update.

Unlike postal mailing addresses, there is no comprehensive database where email addresses can be looked up. Email address verification requires other steps to determine that addresses are accurate, well-formed, and live. Typically email validation uses a hosted solution for identifying and removing invalid and harmful addresses to prevent incorrect contact information from entering your database. Email validation identifies and corrects invalid entries either at the point of capture or at a later stage when addresses have been entered into a database by using a batch validation process.

First, it’s important to check the address syntax. Is the email address well-formed? Typing errors can often be automatically remedied. This includes misspellings, additional spaces, omitted letters in common domain names, and incorrect domains—for example, the use of .com versus .net. The next step is to focus on the domain. Does it really exist? Does it have a mail server to accept email? This is achieved by establishing communication with the relevant ESP’s mail servers. Based on the responses received from the servers, a lot of useful data about deliverability can be deduced. Validation responses reported by Experian’s industry-leading email verification solution include: 

  • Mailbox exists and is reachable.
  • Mailbox exists but is disabled.
  • Mailbox does not exist.
  • Mailbox is full.
  • Mailbox belongs to a role account, such as support@, sales@, info@.
  • Mailbox is likely a spam trap, black hole, or a seed.
  • Mailbox or domain name contains profanity.
  • Domain does not respond to validation requests or does not have any active servers.
  • Domain name is likely a typo (e.g., gmial vs. gmail). Our service also returns suggested corrections.
  • Domain is administered by a disposable email provider (e.g., 10MinuteMail), which could indicate fraud risk.
  • Domain is accept-all, so the specific username cannot be validated.
  • Unknown: unable to conclusively verify or invalidate the address; the request timed out due to the host domain not responding in time.

One question that always arises is: what to do about the unknowns? The number of unknown responses can vary depending on factors like domain responsiveness, mail server configurations, and overall global platform load at the time of validation. Our advice is to be defensive. As indicated above, assuming addresses with a response of “unknown” are valid can lead to unanticipated and expensive results. Sender reputation can be adversely affected in days of improper sending, and it takes weeks to recover.

As most email verification services charge depending on the number of validated emails, it pays to choose a solution where “unknown” responses incur no fees. Services that assume all accept-all domain addresses are valid will certainly deliver a greater quantity of “valid” results, but they also come with greater risk. At Experian, we prefer to focus on quality rather than quantity, and as such, do not charge for unknowns for real-time and batch lookups (outside of professional services engagements). We also recommend users mail to “unknowns” with caution—our word of advice is to include at most 10 percent of “unknowns” into campaigns to minimize overall bounce risks.

Experian’s industry-leading technology verifies business domains, international domains, and consumer domains like Yahoo!, Gmail, Hotmail, and more. Our secure, enterprise-grade solution is hosted in Experian data centers and protected by Experian security standards to help ensure your data is always protected.

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