How To Validate Email Address

Email Regex Strict Validation

How to Validate Email Address

This email regex is a bit complex and meets the following email requirements:


  • hyphen is not the first or last character
  • dot is not the first or last character
  • dot does not appear consecutively
  • tld min 2 characters
  • Note

    Below are samples of valid email addresses.

    Below are samples of invalid email addresses.

    Revisit the email regex again.

    Email regex explanation.

    2.1 A Java example using the above regex for email validation.

    2.2 Unit tests.

    P.S If we want to support extra special characters like +=!$%| in local-part, just put it into the bracket

    Note Please do not put too strict on the email validation as it will reject many valid emails. This email regex strict version is a good balance of what is considered a valid email in most cases.

    P.S. This email regex strict version does not support Unicode.

    Check For Disposable Emails

    A disposable email address is a temporary address that is valid for some time. You should clean your mail of any disposable emails generated by Nada, Mailinator, and similar services. You can make use of a third-party API, such as InboxHit. Those can reliably detect disposable email addresses. Also, you may search for a list of domains used for temporary email addresses and use them in your RegEx.

    Building A Regex Step

    This recipe illustrates how you can build a regular expression step-by-step. This technique is particularly handy with an interactive regular expression tester, such as RegexBuddy.

    First, load a bunch of valid and invalid sample data into the tool. In this case, that would be a list of valid email addresses and a list of invalid email addresses.

    With the basic structure of your text pattern defined, you can refine each part until your regular expression no longer matches any of the invalid data. If your regular expression only has to work with previously existing data, that can be a quick job. If your regex has to work with any user input, editing the regular expression until it is restrictive enough will be a much harder job than just getting it to match the valid data.

    Read Also: How To Get Old Email Back

    Email Verification: Free Or Sustainable

    You have both free and paid tools to verify an email address without sending an email. The question is: which one should you use?

    Free tools like our Free Email Verifier work well for verifying one email address at a time. If you just need a quick check on an email youve found somewhere else, or only send a few outbound emails each week, a free tool may work just fine.

    In contrast, a paid option for email verification can make your outbound email efforts more sustainable. Instead of spending hours verifying email addresses before you ever send a single email, you can work automated verification into your workflow.

    The question now becomes: what do you need?

    What Does The Email Verifier Check

    Advanced email address validation in .NET

    This is the list of validations the Email Verifier performs:

    • Disposable Email Address: We check if the email address has a domainname used for temporary email addresses.
    • Webmail Email Addresses: We verify if the email address uses a webmaillike Gmail or Yahoo.
    • Presence of MX Records: We check if there are MX records on thedomain. If there aren’t, the email address can’t receive emails.
    • Presence of SMTP Server: This check is successful if we are able toconnect to the SMTP server .
    • SMTP Check: We test the email address and see if it bounces or not, withoutsending an email.
    • Accept-all Domain: We check if the server has a catch-all policy thataccepts all the email addresses.

    Also Check: Why Isn T My Email Updating

    Improve Your Team’s Email Response Time By 425% With Emailanalytics

    • 35-50% of sales go to the first-responding vendor.
    • Following up within an hour increases your chances of success by 7x.
    • The average professional spends 50% of their workday on email.

    You can trust this tool to identify and help you remove any inaccurate or invalid email addresses from your list, whether theyre the result of a typo, user abandonment, or malicious intentions.

    How To Verify Email Address Without Sending An Email

    Whether you are sending a cold email campaign or a regular newsletter, the first thing you should do before hitting a Send button is to verify the list of your emails.

    By conducting verification, you clean your email list, filtering invalid and spammy email addresses that cause bounces and hurt your delivery rate.

    Fortunately, you dont have to spend a lot of time verifying each email address from your mailing list manually. The whole process can be run on autopilot.

    In this blog post, well explain in detail why you need to verify email addresses, when to do it, how to verify email addresses without sending an email, and how email verification tools work.

    Recommended Reading: Why Is My Email Not Updating

    How Do I Verify An Email Address Without Sending An Email

    Were glad you asked.

    You have a couple of different options for email verification.

  • Free email verifier tools: If youre sending a low number of emails , a free tool will work great.
  • Email finder tools with built-in verification. If youre scaling email campaigns and dont want to risk bouncing, go with an email finder tool that will automatically find and verify any given email address.
  • Whether you need a handful of verified email addresses or a list of thousands of lead emails, verifying an email address without sending an email is pretty simple.

    Heres how.

    Gmail Special Case For Emails

    How to Validate Email Address in Javascript

    There’s one special case that applies only to the Gmail domain. It’s permission to use the character + character in the local part of the email. For the Gmail domain, the two email addresses and are the same.

    Also, is similar to

    We must implement a slightly different regex that will pass the email validation for this special case as well.

    Let’s also write an example to test this use case:

    Don’t Miss: My Emails Are Not Updating

    How To Check If An Email Is Valid

    Spammers have become so skilled in their craft that one must learn how to check if an email is valid to reliably distinguish legitimate emails from fake ones. In this article, we provide 5 different methods for checking if an email is valid, and most of them are so simple that anyone can follow them with ease.

    No Leading Trailing Or Consecutive Dots

    Both the local part and the domain name can contain one or more dots, but no two dots can appear right next to each other. Furthermore, the first and last characters in the local part and in the domain name must not be dots:

    Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python
    Regex options: Case insensitive
    Regex flavors: .NET, Java, PCRE, Perl, Python, Ruby

    Read Also: How To Print An Email

    Use An Email Finder Tool With Verification

    Most email finder tools offer the ability to verify email addresses. The key is to find a tool that automatically verifies your email address, rather than using up credits or charging you extra to take the verification step.

    A couple of things to look for:

  • Ideally you want a tool that gives you the option to verify emails from a prospecting tool like Sales Nav or upload your list, depending on your workflow.
  • You need a tool that only charges you for verified, up-to-date email addresses.
  • You have a few different options that meet both these criteria.

    • Hunter doesnt validate emails, so they are often outdated.
    • ZoomInfo can provide good data, but is often a budget buster for growing teams. It also becomes outdated quickly, as it will never update as fast as Linkedin profiles will.
    • Wiza finds and verifies email addresses, and is best used in conjunction with LinkedIn Sales Navigator.

    Wiza verifies email addresses as you scrape lead data from LinkedIn Sales Navigator.

    Youll need a Sales Nav account, but setting up your workflow ensures one thing: youre getting up-to-date, verified email addresses for the people youre trying to reach. Finally, youll only pay for verified email addresses.

    Heres how to verify an email address with Wiza:

    • Upload your .csv with the people you want to find email addresses for
    • Select Process List, then Scrape and Find Emails
    • After the search ends, youll be able to download your verified email addresses

    Best Email Address Validator Tools

    How to Check if an Email Address is Valid and Exists or Not

    Youve landed a list of email addresses of people in your target audience.

    Now you can launch the perfect email marketing campaign!

    But wait. Why are so many of these emails not getting delivered? Why are we getting flagged as spam?


    Turns out a good chunk of those email addresses werent real, or werent accurate anymore.

    You didnt get what you paid for/worked for. You wasted time putting that email campaign together. And now youre dealing with spam complaints.


    If only there was some way this could have been prevented

    You know where Im going with this, right?

    The right email validation tool could have saved you here.

    So how do email address validator tools work? And what are the best email validation tools for how to verify an email address?

    Glad you asked

    Recommended Reading: Find All Email Accounts

    How To Verify An Email Address Before Sending Cold Emails

    There are multiple techniques to verify email addresses. Some of them require advanced knowledge of email technology. However, in this section, we have added some easy techniques to verify your email accounts. We have also tried to provide simplified solutions to tackle the technical difficulties associated with it.

    How Does It Work

    In general, email service providers are happy to offer services that validate email addresses. This includes free service providers such as Gmail and others that you might pay for. There are alsofree validation toolsand services that allow you to test email deliverability of the addresses in your mailing lists quickly.

    If your ESP doesn’t offer this service, learn how to validate an email address. You can do this by installing a validity checker or use one that requires no installation and allows you to validate an address online.

    Recommended Reading: Unarchiving Outlook Emails

    Simple With All Valid Local Part Characters

    This regular expression expands the previous one by allowing a larger set of rarely used characters in the local part. Not all email software can handle all these characters, but weve included all the characters permitted by RFC 5322, which governs the email message format. Among the permitted characters are some that present a security risk if passed directly from user input to an SQL statement, such as the single quote and the pipe character . Be sure to escape sensitive characters when inserting the email address into a string passed to another program, in order to prevent security holes such as SQL injection attacks:

    Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python
    Regex flavors: .NET, Java, PCRE, Perl, Python, Ruby

    Which Regex Should I Use

    Validate Email Addresses in Power BI

    In this tutorial, we’ve looked at a variety of solutions using regex for email address validation. Obviously, it depends on how strict we want our validation to be and our exact requirements as to which one solution we should use.

    For example, we can use the simple regex from section 3 if we need just a simple regex to check the presence of an symbol in an email. However, for more detailed validation, we can opt for a stricter regex solution from section 6 based on the RFC5322 standard.

    Finally, if we are dealing with Unicode characters in an email, we can go for the regex solution provided in section 5 of this tutorial.

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    Important Questions To Ask Before Selecting An Email Address Provider

    How to validate email addresses effectively

    When it comes to validating an email address, simply checking for an @symbol is not enough. In order to effectively validate an email address, heres three questions to ask your supplier.

    1) Does the service correct syntax errors?

    Often, developers see syntax errors in the form of a dialog box after inputting a piece of invalid code. When entering email addresses, humans make often make mistakes such as typos. Syntax validation identifies these typos, preventing the capture of inaccurate email addresses, while allowing clean addresses to pass through.

    2) Do you check if the domain exists and that the email address is live and in use?

    Ensuring you use a supplier who checks whether the domain, mail server and the account exists is important. It’s also worth checking if your email validation services checks for Catch All to ensure captured email addresses which are live and in use.

    3) How do I avoid spam traps?

    To anti-spam organisations and inbox providers, falling into a spam trap can make you look like a spammer, which can significantly impact your sender reputation. A bad reputation when it comes to sending emails is something to avoid, because it prevents your emails from getting delivered to the intended recipient.

    There are two types of spam traps, pristine traps and recycled traps, and since they look like regular email addresses, and there isnt a publicly available list, it’s hard to spot them in your mailing list.

    Use An Email Verification Tool

    An email verification tool can help you in doing all the technical verifications at one go. You just need to add the email list, and the automated system will verify all the email addresses for you. The other methods listed above are tedious, and each task has to be done individually. You can use a bulk email verifier tool to verify an email list and get results in a fraction of minute. This will help you in spending less time in email verification and providing your valuable time for cold email campaigns.

    Read Also: How To Find Out Your Icloud Email

    The Benefits Of Email Validation

    Email is one of the most preferred and effective communication channels, but worryingly, only 10% of the email addresses captured are accurate, and the reason for this poor data is human error.

    Only by collecting accurate email addresses, will businesses really get to know their customers, and the use of email validation is by far the most effective way way to ensure quality email address data.

    The key benefits of using an effective email validation tool include increased email deliverability, meaning businesses reach more customers, an uplift in successful email marketing campaigns, a reduction in hard bounces and emails being blocked, helping businesses maintain a positive sender reputation, more efficient onboarding for new customers and a decrease in fake registrations that will clutter databases.

    How Does Email Validation Work

    4 Ways to Verify If an Email Address Is Valid

    Most email service providers provide email validation services. There are many free tools that also validate email addresses ValidateEmailAddress, EmailValidator and Pabbly Email Verification are few of such examples.

    First, you need to bulk upload your list of email IDs. Email validation tools will then make some quick checks to determine whether the email addresses are valid, risky or invalid.

    Valid: This means that the email address exists, and it is error free. This verification will be complete to the mailbox level.

    Risky: This means the recipient exists but there are other factors that indicate that this address could still result in a bounce.

    Invalid: If an email address is marked as invalid, it contains syntax errors, DNS errors and/or mailbox errors.

    Read Also: How To Print Email

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