Sending emails without checking if the addresses are valid is like throwing darts in the dark. Sure, you may land a few hits, but more often than not, you’re just damaging the wall. Thankfully, if you’re reading this, you’re ready to take the other route.
Regularly checking that the emails on your list are valid does more than polish your list. It also protects your sender reputation, boosts engagement, maximizes your ROI, and gives your messages a fair shot at success.
So before you launch your next email campaign, it’s worth taking the time to verify those contacts. This article explores effective methods to help you do just that. But first…
Why Even Bother Checking If An Email is Valid?
Verifying email addresses in your contact list isn't just a best practice—it's a necessity. Why? Because it ensures your messages reach real people who are genuinely interested in hearing from you.
But that’s merely scratching the surface. You also enjoy the following benefits:
- Improve Deliverability: Invalid emails increase bounce rates, which tells email service providers (ESPs) that you might be sending to untrustworthy lists. Over time, this tanks your email deliverability, meaning fewer of your emails make it to inboxes.
- Protect Your Sender Reputation: ESPs track your sender's reputation closely. When invalid or fake addresses repeatedly cause bounces, your reputation takes a hit. And that causes your emails to be marked as spam or blacklisted entirely. Email verification helps you avoid this scenario completely.
- Reduce Costs: Sending emails to invalid addresses is like paying for advertising that no one sees. Besides the cost of the sending software, you also incur the opportunity cost of wasted time and effort. By verifying email addresses, you can cut these expenses and allocate your resources more effectively.
- Boost Engagement Rates: An email list filled with valid contacts directly correlates to better engagement metrics. When you reach real people, you can expect higher open rates, better click-throughs, and, ultimately, more conversions.
- Avoid Spam Traps: Invalid or inactive email addresses can often become spam traps, used by ESPs to identify senders who aren’t maintaining clean lists. Getting caught by a spam trap can seriously harm your ability to reach legitimate subscribers.
Simple Methods to Manually Check If an Email Address is Valid
Before diving into advanced verification methods, there are a few simple ways to manually check if an email address is valid.
To be clear, these manual methods aren't foolproof. They're quick checks to give you a good idea of an email's validity. For larger lists or more certainty, you'll want to use a dedicated email verification tool.
With that said, let’s go through these manual methods.
Check for Proper Syntax & Formatting
The first and easiest way to determine if an email address is valid is by checking its syntax and formatting. Every valid email address follows a basic structure: [email protected]. To break it down, this means a valid email address should include:
- A local part (i.e., the part before the "@" symbol)
- An "@" symbol
- A domain name and extension (the part after the "@")
Checking for proper syntax and formatting helps you catch common errors early on to prevent immediate bounces. We're talking about errors like:
- Starting with or including invalid characters (like spaces or special characters other than dots, hyphens, and underscores).
- Missing an "@" symbol, having it in the wrong position, or having double.
- Missing a proper domain extension (like ".com", ".net", or ".org") after the domain name.
Send a Test Email
Another simple but effective way to check if an email is valid is by sending a test message (where possible) and waiting to see if the email bounces back.
If you receive a "delivery failed" or "mailbox does not exist" notification, it’s a sign that the email is invalid. If the email is delivered successfully, chances are the address is valid and the mailbox exists.
That said, bounces come into two different types: hard and soft. Hard bounces indicate permanent issues while soft bounces signal temporary issues like server problems or full inboxes.
For soft bounces, you may consider trying again after a while if you suspect the email address is still in use. Hard bounces, however, should be scrubbed from your list to protect your campaigns.
Verify Custom Domains
An especially effective email validation technique is to check whether custom domains associated with email addresses are real and operational. After the "@" symbol, every email address includes a domain name (i.e., “@company.com”).
To check if the domain is valid, copy the domain part of the email address and paste it into your browser to see if the domain has an active website. If the website exists, the domain is likely valid.
Alternatively, you can perform a DNS lookup to confirm if the domain has mail servers configured to receive emails. If the domain is nonexistent or inactive, the email address is almost certainly invalid.
Keep in mind that even valid domains might have inactive email inboxes. In other words, this check alone isn’t foolproof but it does give a good indication of email validity.
Look Out for Common Mistakes
Another quick, manual check involves scanning for common errors that people often make when submitting email addresses.
Some frequent mistakes include:
- Misspelling of popular domains: For example, "gnail.com" instead of "gmail.com" or "hotnail.com" instead of "hotmail.com."
- Repeated characters: Typos like "joohndoe" instead of "johndoe."
- Omitted or misplaced dots: People sometimes forget dots or put them in the wrong place, especially in email handles like "johnd.oe."
Simple proofreading or visual inspection can help you spot these small mistakes before they make their way onto your mailing list.
Verify the Email Address through Search Engines or Social Media
Another manual approach is to check whether the email address exists on search engines or social media platforms. You can do this by entering the email address on Google to see if it has been associated with any accounts, public profiles, or listings.
Many email addresses, especially personal ones, might be tied to social media platforms like LinkedIn, Facebook, or X. If you can find the email linked to an existing profile, it’s a good sign that the email is valid.
While this isn’t always the most reliable method (especially with private or less common emails) it can help confirm if a person actively uses the email address. This method is particularly useful for B2B marketers when researching email marketing leads.
Advanced Techniques to Check If an Email Address is Valid
While manual checks are the ideal first step for email verification, advanced techniques provide a deeper level of validation.
These methods are more technical but can significantly improve the quality of your email lists by verifying the status of email servers and addresses at a more granular level. Let's check them out.
Mail Exchanger (MX) Record Check
One of the most reliable ways to confirm the validity of an email address is by verifying its Mail Exchanger (MX) records. MX records are part of the DNS and indicate the mail server responsible for accepting emails on behalf of the domain.
In other words, this check verifies that emails have a destination. It’s especially useful in confirming the operational status of domains.
One way to perform an MX lookup is to open a command prompt or terminal, type "nslookup -type=mx domain.com" (replace domain.com with the email's domain), and hit enter.
If it returns a list of mail servers for that domain, it signals that the domain is likely set up to receive emails. But if no record is found, the email address is likely invalid as there's no mail server to handle incoming mail.
Alternatively, you can use online checkers like MxToolbox to verify the existence of mail servers for email addresses.
Simple Mail Transfer Protocol (SMTP) Verification
SMTP verification is another fairly accurate method for validating an email address because it involves directly communicating with the recipient's mail server.
It involves sending a “ping” to the server to ask whether the email address exists and is capable of receiving messages.
Here’s how it works in practice:
- The SMTP server attempts to establish a connection with the recipient's server.
- Without actually sending an email, the server asks if the email address in question is valid and capable of receiving mail.
- If the server responds positively, you know the address is valid. If not, the server rejects the connection, indicating an invalid address.
This method is more thorough than basic syntax or domain checks because it confirms not only that the server exists but that the specific email address is active and capable of receiving emails.
Blacklist Check
Another advanced technique is performing an email blacklist check to ensure that the domain or email address hasn’t been flagged by spam filters or added to blocklists.
If an email address or its associated domain is blacklisted, it's often a telltale sign of suspicious activity, and you should avoid sending emails to that address. Your emails will likely bounce or end up in spam folders anyway, regardless of their validity.
The easiest way to conduct a blacklist check is to use an online checker like ZeroBounce or MxToolbox to scan email addresses or domains against known spam and blocklists.
Catch-All Domain Detection
Catch-all (or accept-all) domains are configured to accept any email sent to their domain, even if the specific email address doesn’t exist. Businesses use these domains to ensure no emails are lost due to misspelled addresses or variations
The problem is that including catch-all domains in your list inflates it with addresses that may never lead to actual engagement.
Plus, targeting these domains often leads to high bounce rates because the email server accepts the message even when there’s no actual mailbox for the address. So while these domains aren’t invalid, it’s best to steer clear of them if possible.
You can use DNS queries or SMTP validation to detect domains configured as a catch-all. If it is, proceed with caution, as it’s unclear whether your message will reach a real recipient.
Streamline Email List Validation With Instantly.ai
At the end of the day, verifying email addresses—whether via manual or advanced methods—can be time-consuming and prone to errors, especially when dealing with large lists.
The good news? Specialized email validation tools like Instantly.ai can help you skip all the hassle.
Instantly automates the entire email verification process, saving you time while ensuring that your email list is clean, accurate, and ready for outreach. All essential checks are taken care of in one seamless sweep—syntax validation, MX record verification, SMTP authentication, etc.
Instantly also tackles more complex issues, like catch-all detection, ensuring that you’re only engaging with valid, active email addresses.
Whether you’re sending a few hundred emails or several thousand, Instantly is tailor-made to handle your workload. Keen to avoid costly bounce-backs and maintain exceptional deliverability without checking every single email on your list? Try Instantly today at zero cost!
Best Practices for Building and Maintaining a Valid Email List
Maintaining the validity of contacts in your email list is an ongoing endeavor. And that means you need to be proactive when it comes to keeping out invalid accounts.
Apply these best practices to do just that:
- Use CAPTCHA or Email Verification Plugins for Forms: Adding CAPTCHA or verification plugins to your signup forms helps prevent fake signups from bots and reduces invalid or spammy email addresses.
- Use Double Opt-In: With double opt-in, subscribers who signed up for your email list must first confirm their email addresses before receiving any emails. This practice helps ensure only real, interested people make it onto your list.
- Remove Hard Bounces Regularly: Hard bounces indicate permanently invalid or non-existent email addresses. Routinely removing them is vital to keep your list fresh and prevent damage to your sender score.
- Avoid Purchasing Email Lists: Buying pre-compiled email lists is often associated with poor quality and high bounce rates. However tempting this 'quick fix' may seem, it's much better to build your list organically through opt-in methods.
- Set the Email Honey Pot Trap: The honey pot trap is an advanced tactic for weeding out auto submissions that may pass other validation checks. Simply include an invisible form field to your sign-up form that only bots can see. When a bot fills out this hidden field, it's flagged, and their email is automatically blocked from your list.
Key Takeaways
If email plays a major role in your broader marketing strategy, then verifying contacts in your email list is the simplest way to get better results.
Short on time? Here’s a quick rundown of the highlights:
- By taking the time to verify your email list, you protect your sender reputation, increase engagement, and ultimately, drive exceptional outcomes for your marketing campaigns.
- When trying to check if an email is valid, start with manual checks like ensuring proper syntax, sending a test email, and looking up the domain in search engines and social media.
- If manual checks don’t work, you can move on to advanced techniques like looking up MX records, verifying SMTPs, or running a blacklist check.
For the best results, you’ll want to engage with dedicated email validation software (like Instantly.ai). Specialized validation services are equipped to run these checks automatically, which means no hassle trying to figure things out on your end. Sign up for a free trial today!
