How To Check an Email Address Online (and Why You Need To!)

It’s astounding: more than 306.4 billion emails are sent every day, a figure that’s expected to reach 361.1 billion by 2024. However, 20% of those emails will never reach their destination, according to research from Return Path. Part of the solution: learning how to check an email address online prior to sending.

Why You Need to Check Email Availability

In a competitive marketing area like email marketing, where the average person gets about 121 business emails every day, it’s becoming harder to stand out in the inbox. But first, you need to actually make it into their inbox.

For businesses and entrepreneurs who rely on good email marketing and communication, a 20% nondelivery rate is a staggering number that can have a direct impact on your success. On average, this means that one in five emails will never reach your recipient. Undelivered emails can’t be opened, and unopened messages can’t fulfill their purpose.

Also, if you’re sending a message to invalid addresses, it results in a hard bounce. Too many of these hard bounces can damage your sender score, which makes you more likely to go straight to the SPAM folder. Too many SPAM signals can eventually have you blacklisted from the server, which means none of your emails to that server will be allowed through.

Part of the problem comes from having dirty email data. Maybe you have addresses on your list that are no longer in service. Or maybe there are spelling or syntax errors, such as a missing period or “@” symbol.

Some good news: you can check email address validity online using a fast, simple process and improve your delivery rate.

How to Check Email Address Availability: Step By Step

Tools that check email online are becoming a must-have for businesses who use email marketing. Every tool works a little differently, but the process remains largely the same. Here’s a rundown on what you’ll need to do:

1. Choose an Email Verification Tool

A simple Google search for “how to check email address” will net you several results for email checker tools. You can spend time checking out each one, or you can read our recent blog post on some of the best free email verification tools. We also included a few other best tools to check email addresses online in the next section.

When vetting an email verifier, you’ll want to pay attention to a few features.

First, the cost. Some tools will let you check a number of addresses for free. This can be super helpful for small businesses with short lists, as you don’t have to pay a dime to use it. Some tools will charge on a recurring subscription basis, while others offer pay-as-you-go credits.

Also, consider their success rate. Some tools share their false positive rate, and the lower this rate, the better for you.

Last but not least, look at their processes. Comprehensive tools that check email address availability leave no stone unturned: syntax check, domain record check, role-based account detection, honeypots, disposable address detection, and extended SMTP verifications, among others. You don’t have to know what all of these things are, but you should take comfort knowing the tool is thorough.

2. Prepare Your Mailing List

Once you choose your tool to check email availability, you’ll need to look into their list requirements. Most tools will accept a .CSV file of all your email addresses. Some tools accept other formats, such as an Excel sheet.

Once you know your file type, you’ll need to input your mailing list into that format. The more organized your file, the better the tool can make sense of your data and generate the best results.

3. Generate Results

Load your mailing list file into the tool and wait for results. The time this takes can vary, depending on the complexity and size of your list and the tool itself. Many tools will send you a message when your results are ready. Depending on the tool you use, you may be able to download your results in the file format of your choice.

Now you have a clean list that you can feel confident about using in your email marketing!

Best Tools to Check Email Addresses Online

If you need to check email address validity to clean up your list, these tools have you covered:

1. Debounce

DeBounce is one of the most user-friendly email checker tools you’ll find anywhere. Upload your list and DeBounce will find non-existent, spammy, or inoperable addresses and remove them from your list.

You can try DeBounce for free, no credit card required. Once your trial is up, email checks start at just $0.0003 per address.

2. VoilaNorbert

VoilaNorbert is a powerhouse in email for two reasons: first, it can help you find someone’s address if you don’t already have it. And second, it can help you validate thousands of email addresses for a very low cost.

Their estimator tool is helpful: just type in the number of addresses you need to verify and get a no-frills, upfront cost so there are no surprises.


With nearly 400 positive reviews on Capterra, is a clear favorite. More than 500K users trust its 95% accuracy rating. One of its strong suits is its email locator: when you have a bad mail address, you can use the tool to find the correct address. This helps you avoid list shrink so you never have to miss out on leads. It’s also an ideal solution if you prefer a subscription-based service instead of a pay-as-you-go plan.


Taking the extra step to check addresses online can be one of the most impactful things you do for your marketing strategy. When you’re sending to good email addresses, your sender score gets a boost. But more importantly, you have more opportunities to connect with real people who might turn into paying customers.

How to Check Email Address - FAQs

How do I check if an email address is active?

Inactive addresses can kill your sender score. If you want to check an email account online, use a free verification tool like Debounce or MyEmailVerifier before adding the address to your list.

How often should I check email address lists?

Mailing lists are evolving documents that should be reviewed frequently. It’s recommended that you check mailing lists every three months if you’re a frequent sender, or at least once per year if you send emails 1-2 times a month.

Can I check email address validity online?

Yes, you can do it online. Use a verification tool like EmailVerifier or VoilaNorbert Verify to validate addresses before sending.

What are the best email checkers for Mac?

One of the most comprehensive mail checkers for Mac is DataValidation, which also helps with list segregation and list quality. Email Hippo is also one of the best list checkers for Mac, which allows you to check up to 500,000 addresses per day.