Is This Email Address Valid? Here Are 5 Ways to Check | Email Verification API | WhoisXML API

Email Verification Blog &
How To Guides to Obtain Email Verification Data

Read the other articles

Is This Email Address Valid? Here Are 5 Ways to Check and Why It Matters

Download PDF
Is This Email Address Valid? Here Are 5 Ways to Check and Why It Matters

Based on research data, the global email user base will be increasing by 2-3% every year until it reaches 4.4 billion users in 2023. So, more than ever, email marketers need to be able to answer the following questions: Are all the email addresses in my recipient lists valid? Will my messages be able to reach intended recipients or not? Also, do any of my collected addresses have ties to malicious activity?

Each day, users send an average of 54 billion legitimate emails across the globe. Interestingly, a whole lot more malicious spam messages get sent, averaging 302.99 billion a day. When threats are everywhere, the mere act of opening spam could lead to becoming the next victim of phishing or an even more sinister attack.

On the other side of the fence, meanwhile, marketers are worried that their messages may not reach the right people. A lot of organizations suffer from high bounce and low open rates, with adverse effects on their marketing efforts. Sadly, no matter how great your campaigns are, if your emails do not reach loyal customers or leads of interest, your efforts are bound to go down the drain.

To alleviate these and other issues, organizations need a means to be able to check the validity of email addresses they come in contact with. So, email verification with products such as Email Verification Lookup or its counterparts Email Verification API or Email Verification Bulk API can be integral to any company’s successful and efficient operations. To illustrate how these tools work exactly, we listed down five supported email checks in this post.

5 Ways to Check If an Email Address Is Valid

1. Detect Disposable Email Addresses

No reputable individuals or companies are likely to use disposable email addresses. So why bother spending time and effort on low-quality recipients when you could remove them from your distribution list right away for better results?

Email Verification Lookup/API instantly checks if an email address is disposable. It can weed out all temporary email addresses obtained from 10MinuteMail, Mailinator, GuerrillaMail, and other providers. A valid email address, on the other hand, when queried through Email Verification API, should display the following result:

Detect Disposable Email Addresses

Why is detecting disposable email addresses a must?

Doing so can help marketers improve their email marketing performance. By making sure that only valid and active email addresses are part of their campaigns, they can protect their email deliverability as they get rid of addresses that are likely to bounce in the near future.

When integrated into sign-up forms, Email Verification API can also detect disposable email addresses that may be used by freemium abusers to sign up for trial periods repetitively (thus without bringing in any revenue). Email verification users can even disallow subscribers from using disposable email addresses while registering in the first place.

What’s more, cybercriminals often use disposable email addresses to mask their identities when conducting scams. Avoiding these addresses altogether is thus a good cybersecurity practice.

2. Check If an Email Address’s Inbox Can Receive Messages

For an email address to work, it must have access to a corresponding mail server. And users can verify the existence of one by checking for a Simple Mail Transfer Protocol (SMTP) connection and valid mail exchanger (MX) records.

Email Verification Lookup/API automatically checks for these elements with every email address query. A valid email address, therefore, should have results similar to this:

Check If an Email Address’s Inbox Can Receive Messages
Check If an Email Address’s Inbox Can Receive Messages

Why is checking if an email address’s inbox can receive messages a must?

For marketers, communicating with existing and potential customers is crucial. But if the email addresses on their distribution lists don’t have corresponding inboxes, their messages simply won’t reach intended audiences. And so, these email communications, whatever their purpose, are bound to bounce as well. In turn, a continued increase in bounce rate is also bound to heighten their chances of landing on a spam blocklist if not alleviated.

3. Catch Syntax Errors

Every email address needs to follow a format specified by the Internet Engineering Task Force (IETF). Any address that fails to do so is deemed invalid. Ideally, an email address should have three components:

  • Local address (typically the inbox owner’s name)
  • Domain name (usually the organization’s name)
  • Domain identifier (the top-level domain [TLD])

In the email address john_doe@company[.]com, for instance, “john_doe” is the local address, “company” is the domain name, and “.com” is the domain identifier.

When queried on Email Verification API, a valid email address should have this result:

Catch Syntax Errors

Why is catching syntax errors a must?

Sending emails with misspellings and formatting errors can result in one of two things: they will either bounce or be directed to a catch-all inbox (which will be discussed in more detail in the next section). Whatever course of action is taken, however, the end result is the same — the email won’t reach its intended recipient. To marketers, that means a lost business opportunity. To security teams, that means an increased likelihood of landing on someone’s blocklist.

4. Determine Catch-All Email Addresses

Many companies use catch-all email addresses to ensure that none of the messages intended for a staff member falls through the cracks. Catch-all email addresses accept emails meant for even misspelled local addresses (i.e., wrongly spelled employee or department name) or domain names. So when a prospective customer sends an inquiry to say, slaes@samplestore[.]com instead of sales@samplestore[.]com, Samplestore will still get the message despite the misspelled department name if it uses a catch-all email address.

Email Verification Lookup/API can help marketers and security professionals alike in that it checks if an email address is a catch-all. On Email Verification API, a non-catch-all email address would return the following result:

Determine Catch-All Email Addresses

Why is determining catch-all email addresses a must?

While using catch-all email addresses prevents businesses from missing out on opportunities, it can also prevent marketers who are specifically targeting an employee but misspelled his/her name, for example, from communicating with the intended recipient. On the other end of the spectrum, meanwhile, cybercriminals are also fond of using catch-all email address lookalikes for their schemes.

5. Avoid Spam Traps

For marketers, an email address does not only need to be active to count as valid. That is especially true if they deal with users who are part of companies that use spam traps or active but abandoned email addresses. These spam traps allow organizations to detect email senders who illegitimately add email addresses to their lists without user consent.

Email Verification Lookup/API enables users to see if an email address has a corresponding mailbox without sending an actual message. It does so via an SMTP check along with a scan for MX records. On Email Verification API, an email address that isn’t likely to be a spam trap should display these results:

Avoid Spam Traps
Avoid Spam Traps

Why is avoiding spam traps a must?

Marketers whose distribution lists include spam traps may suffer deliverability issues, especially if the spam trap users report them to their Internet service providers (ISPs) as spammers. Also, spam traps are not connected to any real recipient, so sending message to these addresses won’t produce any result.


All that said, the question, “Is this email address valid?” is indeed a critical one to ask. Organizations need to subject every email address coming their way to numerous tests if they want to ensure good deliverability, keep their email reputation intact, as well as steering clear of threats that rely on insufficient email security.

Whether for improving marketing results or mitigating security risks, they can rely on solutions that allow quick checks on any email address such as Email Verification Lookup and Email Verification API.

Download PDF Read the other articles
Try our Email Verification API for free
Get started
Have questions?

We are here to listen. For a quick response, please select your request type or check our Contact us page for more information. By submitting a request, you agree to our Terms of Service and Privacy Policy.

Or shoot us an email to