Email Validation Best Practices: Keep Your Subscriber Lists Clean

An updated email list is critical to a successful email campaign and realizing the return on investment. Here we look at email validation best practices to keep your subscriber lists clean and help your campaigns hit the mark.

On average, email lists decline by 22.5% each year due to natural subscriber attrition, when people leave companies or change their personal email addresses. Email experts suggest that your lists need to be maintained regularly. Without regular email list verifications, invalid and abandoned accounts will begin to accumulate in your database, resulting in bounce backs and your content not being read.

Address this issue head on, with these email validation best practices:

1. Verify your customer emails to achieve inbox delivery

We have released an email validation service to help businesses verify their subscriber lists. Using it is very simple: you just need to add email API to any forms where you collect customer data, from web forms to landing and contact pages to confirm emails in real-time without sending a message. This process acts as the first line of defense in ensuring accuracy for both new and existing email lists.

When you send an email campaign to thousands of email addresses, imagine how much a more accurate list will benefit your marketing program. Not to mention there are some additional benefits to the email validation service:

Maintain your IP/domain sending reputation

A sender score is like a credit score, it signals to email providers the trustworthiness of your outgoing emails. Sending to a bad email list will either force the emails to bounce or land in the spam folder. Most marketing experts agree that bounce rates shouldn’t be more than 3% to 5%. High bounce rates damage your sender score and send a red flag to Internet Service Providers (ISPs) about your mailing practices.

Protect against blacklisting

Invalid, broken, and misspelled email addresses lead to spam and ISP block issues. Our email validation service helps you avoid the case of recipients marking you as spam, which can contribute to your emails getting blocked in the future.

Uplift your revenue opportunity

A more accurate and verified list helps get your emails to the right audience increasing your chances of converting users into paid customers. With any email campaign, segmenting and sending your content to the right audience ensures your content gets read and converts leading to a higher ROI on your efforts.

Reduce the cost of sending emails

Sending emails to invalid or non-existent accounts is money lost. Accurate lists that come with email list verifications help you get higher results from your email efforts.

Use smart data insights

To harness the power of campaign insights starts with using quality data. Not only does it allow you to accurately profile your audience so your messaging is on point but gives you a more complete picture of how your campaigns perform over time so you can measure the direct impact on ROI.

2. Turn email addresses into sales opportunities

People mistype their email addresses all the time. For example, can easily become and it usually gets discovered when the email was undelivered. With our built-in suggestion service, we’ll return the email address with an invalid status and suggest a potential valid value instead.

3. Flag and remove suspicious emails

Your goal is to get emails delivered to real people, so you can build better engagement with your customers. Emails, such as help@, associate with a company, department or a group of recipients and not a real person. And disposable emails are temporary addresses known to be used by spammers. Our email verification API will identify invalid emails addresses you can remove them from your list. This will help reduce high bounce rates and SPAM complaints.

How to start validating emails

If you’re an existing Infobip Email user, you can contact your account manager to add email validation as a service. The service can be used over API or our Portal. The report results can then be downloaded as an .xls or text file formats. Invalid email addresses can be exported and removed directly from your own subscriber database. If you’re using our portal, all invalid emails can be uploaded to the blacklist service. The blacklist automatically filters bad addresses each time you want to send a campaign.

How email validation works using Infobip Portal

Begin validating emails using Broadcast in the portal:

  • Upload the subscriber email list to People module
  • Select tag, segment or people form Target module
  • Manually type in email addresses you wish to validate

How email validation works over API

API examples and a more detailed explanation of using API for email validation can be found on

Response API format

If successful, the response header HTTP status code will be 200 OK include email validation in the response body. If you try to send email validation request without authorization, you will get a response with HTTP status code 401 Unauthorized.


Parameter Type Description to String Destination email address being validated. validMailbox Boolean Check with Email Service Providers and returns true if the email is valid and exists; false if the email is invalid or not found, or unknown if the SMTP request could not be completed. validSyntax Boolean Runs the email segments across a valid known provider rule list. If a violation occurs this value is false. Value is true whenever you are dealing with a correctly composed email address. didYouMean String Null if nothing, however if a potential typo is made, the closest suggestion is provided. disposable Boolean If the domain is in a list of disposable email addresses, this will be appropriately categorized roleBased Boolean Checks the mailbox portion of the email if it matches a specific role type (‘admin’, ‘sales’, ‘webmaster’)

Dec 13th, 2018
4 min read