6 mistakes you’re probably making with email validation

Currently, over half of the world’s population uses email. According to the Radicati Group, the number of email users around the world is set to reach 4.2 billion by the end of 2022, and the number of emails sent and received each day will rise to over 333 billion by the same time.

So, collecting the correct email address has never been so crucial. Important communications, letting customers know when goods or services will be arriving, marketing efforts, and much more are all wasted if an invalid email address is entered into an online form.

There is still a huge number of websites making basic fundamental mistakes when it comes to email. So, what can businesses do to ensure they are capturing accurate email addresses while reducing form friction? Here are the top errors that we have come across, and our top tips for improving email capture.

Mistake 1 - Making people enter their address twice

One way some retailers are attempting to stop invalid emails infiltrating their marketing lists is through the confirm email or double entry field.

Typing is tiresome - so entering anything more than once is a huge no-no – especially if using a mobile device. Every additional field means extra work, which in turn means increased risk of errors and a potential reduction in completion rates. Your users are probably going to try to copy and paste the email address from the first line anyway so they are just as likely to enter it incorrectly twice.

Whilst an effective email validation tool is a no-brainer for capturing accurate email addresses, it can’t of course check whether the address belongs to someone else. The only way to be sure that the address you get belongs to the person who signed up is to send a confirmation email with a unique link (for double opt-in). Unfortunately, there is always going to be the chance of the user forgetting to click the link in the email. However, this is the only real way to confirm that the person signing up for your list actually wants to hear from you, and it is far better than punishing the user with typing the email twice. Double opt-in lists have also been shown to get up to double the clicks and double the opens of single opt-in lists. They also get half the hard bounces and half the unsubscribes of single opt-in so it’s a win all round.

Mistake 2 - Not using inline validation

There are few things more infuriating, once you’ve filled out a form and hit submit, than being served with the same page again, flooded with angry red error messages about fields you’ve filled in incorrectly. Inline verification is a great way of avoiding user confusion by correcting field errors along the way.


Here, Twitter makes use of dynamic messaging on the right hand side of the field to alert the user to the fact they already have an account with them. Brownie points to Twitter for also giving the user options to rectify the problem by logging in or recovering an existing password.

Mistake 3 - Being too restrictive

Being too strict with your validation is a sure fire way to lose yourself some customers. Does your address tool account for the various characters people use in their email address such as slash (/), equal sign (=) or exclamation (!)? These are all valid symbols, so if you’re software is rejecting these you are literally turning potential customers away.

Mistake 4 - Regex validation

Using a regular expression (or regex) is another common way to validate email addresses. Whilst being easy to implement, these often fall into the trap of being too restrictive. A regex to validate email addresses ends up being more complicated than you first think once you’ve read the RFC ( a 47 page technical spec describing what a valid email address is) pertaining to SMTP (Simple Message Transfer Protocol and email addresses. It’s something that most people presume will be easy, until you drill into it and figure out just how complicated it can be. 

Mistake 5 - HTML5 form validation

HTML5 includes its own validation techniques for input types, so by setting the field type to “email” and using the new required attribute on a field you can get the browser to do the validation for you. This is all nice and easy, but validation is subject to the browser the visitor to your website is using. Some browsers will just validate the @ symbol exists in the form of something@something, while others look for something@domain.somewhere. Obviously this is not foolproof and gives no guarantee that an address actually exists.

Mistake 6 - Not providing clear labels

Personal data is the currency of the online world. Only by providing clear labels about how and why you need their email address will your users be inclined to part with it. Providing this information clearly can prevent them abandoning your form.

Find out more about how Loqate can help you improve your email data