How to Check Email Addresses in Real Time and Build a Healthy Email List

If you ask them what their best performing channel is, most marketers will tell you it’s email. Several business owners I interviewed have told me that as much as 90% of their sales happen via email. However, all these people pay attention to one vital aspect: they use healthy, accurate email lists. How can you do the same?

For starters, you can validate your email list in bulk to ensure you reach people’s inboxes. But did you know you can also check email addresses in real time and thus keep your database healthy longer?

If you’ve never pruned your list, you probably have many questions: how does it help me and how do I do it? What’s the difference between bulk and real-time email verification?

No worries: I’ll walk you through the steps and share my best tips to help you build a better email list.

What is email list validation

Email validation, email verification, or email list cleaning – as the industry also refers to it – is the process of separating the good email addresses from the bad ones.

You may know that emailing low-quality contacts affects your sender reputation. When Internet service providers (ISPs) decide where your email should go, your reputation as a sender is what helps them make that decision.

So, if you ignore your email list hygiene, you’re telling ISPs email marketing is an afterthought for you. Next thing you know, your campaigns will land in people’s spam folders. Moreover, when you continue to email bad email addresses, your messages may never even make it to your subscribers’ mailboxes – not even to spam. It’s like throwing money out the window, so you’re better off not sending any emails at all.

Fortunately, you can fix poor list hygiene easily and avoid running into such issues. Keeping a neat database should be a central part of your email marketing strategy. Plus, it’s a fast process, so let’s see how you can get started!

How to check email addresses in real time

Like most marketers and organizations, you probably work consistently on growing your email list. The more subscribers you get, the higher your conversions, right? That’s true, but only when your subscribers are real and engage with your content.

How can you make sure you’re gathering legitimate subscribers? Sometimes, people use disposable email addresses only to download a freebie from you. Also, certain subscribers may turn out to be spam complainers – they’ll label your email as “spam” and tarnish your reputation.

“The most effective way to keep these types of addresses off your list is by using an email verification API (Application Programming Interface),” says Josh Brown, Digital Marketing Consultant at Helpjuice.“Look at it as a filter that works in the background to protect your email hygiene. As soon as you install it on your registration and subscription forms, the API will start rejecting undesirable addresses – and it will do so in real time,” Brown adds.

Email addresses you don’t want on your list

I can hear you wondering: what kind of bad email addresses will the API reject? Of course, it depends on the email validation company you choose. Some services offer basic features and can’t detect certain risky accounts. Others use more complex algorithms and can keep away a variety of addresses you don’t want on your list.

Let’s take a close look at some of them to understand why you should avoid them.

Misspelled emails

Typos are one of the most common causes of poor list hygiene. It’s easy to understand why: people often subscribe to emails while using their phones. They misspell one word and instead of getting a new subscriber, you get a bounce. The great thing about having an active API on your site is that it’ll not only reject a misspelled addressbut also suggest your subscriber a correction right away.

Disposable emails

Lead magnets are a great way to grow your email list. But while you have the best intentions, some of your website visitors may just want to get your content offer and leave. So, they use a disposable (or temporary) email address which quickly self-destructs. Temporary emails only cause your bounce rate to go up and send ISPs a poor signal.

Abuse emails

Do you often mark emails as “spam”? Then you may have what the industry calls an “abuse email.” These accounts have a history of complaining about emails they get. Since they’ve frequently hit the spam button on other senders, they may do the same to you. Once you get a good email validation API, you can set it to where it won’t allow complainers to subscribe.

Catch-all emails

These email addresses are not necessarily bad per se. Nonetheless, they’re prone to bounces so they do pose a risk to your inbox placement. Sometimes, to ensure they don’t miss any messages sent to their domain, companies will set their servers up to accept all emails. Even emails sent to addresses that don’t exist.

For instance, may not exist, but as long as you send your email to, it will get there if the server is catch-all. You may think: but that’s great because my email will reach someone at Yes, but here’s the catch (pun intended): that company may decide anytime to turn off their catch-all configuration. So you’ll get a big, fat, hard bounce.

What’s more, catch-all mailboxes become full easily due to the high volume of email they get, and that will result in a soft bounce.

These are just a few of the most common risky contacts you could acquire. Using a reliable API to check email addresses in real time will help you keep these contacts at bay and your reputation intact.

When to prune your list in bulk

Before you get an API, you might want to run your list through a bulk email verifier first. This way, you make sure you start with a clean database. The API will help you keep it clean longer, but if it’s messy to begin with, that won’t help much.

How do you prune your list in bulk? Easy peasy: most email verification companies don’t ask you to download any software. Instead, you upload your email list on the platform and the system will start validating it.

When you download your results, you should see a clear breakdown of the email addresses you had on your list. Of course, you’ll want to ditch the bad ones and resume your email marketing by using only high-quality data.

Now, let’s say you cleaned your list in bulk and you also installed an API. Great! You’re already on your way to better inbox placement and higher engagement. But while the API protects your list effectively, keep in mind you’ll still have to validate it in bulk occasionally.

Why? Here are just two reasons:

Unengaged subscribers

Not all your subscribers will open every email you send. In fact, some of the people on your list may start ignoring you, even if they engaged with you in the beginning. What should you do about it?

“First, you could run a reengagement campaign. Whether you send out an offer or just a quick ‘do you still want to be on our list?’, this will allow you to see who still cares about your emails,” says Uwe Dreissigacker, CEO of InvoiceBerry.

For various reasons, there will be a few subscribers you’ll never win back – and that’s fine. However, keeping them is detrimental. Instead, consider removing people who haven’t opened in more than six months.

First, because ISPs will take their lack of engagement as a sign that you’re not relevant, so they may start to think you don’t belong in the inbox. Then, some of those subscribers may have abandoned their addresses. Be especially careful with Yahoo contacts: if you see more Yahoo emails bouncing than usual, it’s because the email provider is disabling inactive accounts. Remove unengaging Yahoo usersahead of time so you can prevent bounces.

Another reason you should weed out inactive subscribers is that some email addresses maybe turned into spam traps.

What are spam traps?

Their impact on your sender reputation is dramatic. ISPs and blacklist providers set them up to lure in and block spammers, so if your email hits a spam trap, you may be mistaken for a spammer, too. And guess where spammers belong.

Recycled spam traps are some of the most common ones: they’re old, abandoned email addresses that ISPs repurpose to prevent spam. So, this is just another reason why you should remove contacts that have stopped opening your emails. You never know which ones have been turned into spam traps.

Why a healthy list is more valuable than a large one

Let’s face it: we all love seeing our email lists grow. It’s a form of validation: whenever they subscribe to our emails, people tell us how much they like our stuff. While that reinforces our self-confidence and can be a great motivator, it pays off to check those numbers consistently.

How much of your new subscribers are real and contribute to your growth? There’s only one way to find out: keep an eye on your metrics and make sure your email list is always healthy. Otherwise, you’re not only spending money to email dead leads but you’re also depriving your legitimate subscribers of your great content.

Author Bio

Corina Leslie is the PR Manager for email validation company ZeroBounce, an Inc. 5000 honoree. Most often, you’ll find her on the ZeroBounce blog, where she shares her tips and interviews experts on digital marketing and PR. Find her on LinkedIn and Twitter.

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