That is not a valid email address

How to validate an email address in PHP

I have this function to validate an email addresses:

Is this okay for checking if the email address is valid or not?

16 Answers 16

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The easiest and safest way to check whether an email address is well-formed is to use the filter_var() function:

Additionally you can check whether the domain defines an MX record:

But this still doesn’t guarantee that the mail exists. The only way to find that out is by sending a confirmation mail.

Now that you have your easy answer feel free to read on about email address validation if you care to learn or otherwise just use the fast answer and move on. No hard feelings.

Trying to validate an email address using a regex is an «impossible» task. I would go as far as to say that that regex you have made is useless. There are three rfc’s regarding emailaddresses and writing a regex to catch wrong emailadresses and at the same time don’t have false positives is something no mortal can do. Check out this list for tests (both failed and succeeded) of the regex used by PHP’s filter_var() function.

Even the built-in PHP functions, email clients or servers don’t get it right. Still in most cases filter_var is the best option.

If you want to know which regex pattern PHP (currently) uses to validate email addresses see the PHP source.

If you want to learn more about email addresses I suggest you to start reading the specs, but I have to warn you it is not an easy read by any stretch:

You can use filter_var for this.

In my experience, regex solutions have too many false positives and filter_var() solutions have false negatives (especially with all of the newer TLDs).

Instead, it’s better to make sure the address has all of the required parts of an email address (user, «@» symbol, and domain), then verify that the domain itself exists.

There is no way to determine (server side) if an email user exists for an external domain.

This is a method I created in a Utility class:

It can return a true or false when supplied with the FILTER_VALIDATE_EMAIL param.

This will not only validate your email, but also sanitize it for unexpected characters:

After reading the answers here, this is what I ended up with:

Answered this in ‘top question’ about emails verification https://stackoverflow.com/a/41129750/1848217

For me the right way for checking emails is:

Of course, you can show some warning or tooltip in front-end when user typed «strange» email to help him to avoid common mistakes, like no dot in domain part or spaces in name without quoting and so on. But you must accept the address «hello@world» if user really want it.

Also, you must remember that email address standard was and can evolute, so you can’t just type some «standard-valid» regexp once and for all times. And you must remember that some concrete internet servers can fail some details of common standard and in fact work with own «modified standard».

So, just check @, hint user on frontend and send verification emails on given address.

If you want to check if provided domain from email address is valid, use something like:

This is handy way to filter a lot of invalid email addresses, along with standart email validation, because valid email format does not mean valid email.

Note that idn_to_ascii() (or his sister function idn_to_utf8() ) function may not be available in your PHP installation, it requires extensions PECL intl >= 1.0.2 and PECL idn >= 0.1.

Also keep in mind that IPv4 or IPv6 as domain part in email (for example user@[IPv6:2001:db8::1] ) cannot be validated, only named hosts can.

Nowadays, if you use a HTML5 form with type=email then you’re already by 80% safe since browser engines have their own validator. To complement it, add this regex to your preg_match_all() and negate it:

theres is a better regex built in FILTER_VALIDATE_EMAIL but any regex can give bad results.

You might want to consider using an API like Real Email which can does in depth mailbox inspections to check if the email is real.

There are three RFCs that lay down the foundation for the «Internet Message Format».

The RFC 5322, however, defines the e-mail IDs and their naming structure in the most technical manner. That is more suitable laying down the foundation an Internet Standard that liberal enough to allow all the use-cases yet, conservative enough to bind it in some formalism.

They are not exactly interested in implementing a technically all-encompassing definition that allows all the forms (IP addresses, including port IDs and all) of e-mail id. The solution suitable for their use-case is expected to solely ensure that all the legitimate e-mail holders should be able to get through. The definition of «legitimate» differs vastly from technical stand-point (RFC 5322 way) to usability stand-point(this solution). The usability aspect of the validation aims to ensure that all the e-mail IDs validated by the validation mechanism belong to actual people, using them for their communication purposes. This, thus introduces another angle to the validation process, ensuring an actually «in-use» e-mail ID, a requirement for which RFC-5322 definition is clearly not sufficient.

Second requirement typically involves, sending a standard response seeking e-mail to the inputted e-mail ID and authenticating the user based on the action delineated in the response mechanism. This is the most widely used mechanism to ensure the second requirement of validating an «in use» e-mail ID. This does involve round-tripping from the back-end server implementation and is not a straight-forward single-screen implementaion, however, one cannot do away with this.

A typical regex that can satisfy this requirement is: ^[^@\s]+@[^@\s.]+.[^@\s.]+$ The above regex, follows the standard Perl regular-expression standard, widely followed by majority of the programming languages. The validation statement is: @.

For those who want to go one step deeper into the more relevant implementations, they can follow the following validation methodology. @

Those who are interested to know the overall process, challenges and issues one may come across while implementing the Internationalized Email Solution, they can also go through the following RFCs:

RFC 6530 (Overview and Framework for Internationalized Email) RFC 6531 (SMTP Extension for Internationalized Email) RFC 6532 (Internationalized Email Headers) RFC 6533 (Internationalized Delivery Status and Disposition Notifications) RFC 6855 (IMAP Support for UTF-8) RFC 6856 (Post Office Protocol Version 3 (POP3) Support for UTF-8) RFC 6857 (Post-Delivery Message Downgrading for Internationalized Email Messages) RFC 6858 (Simplified POP and IMAP Downgrading for Internationalized Email).

That is not a valid email address

I have a mailing list with nine emails. This morning it worked fine. Now instead of putting the email addresses in the To space it puts the name of the List and when I send I get <> is not a valid email address because it is not of the form user@host. You must correct it before sending the email.

Chosen solution

I am glad I am not the only one. My list name is two words, it has been working fine for years. How can I fix it please. All of my lists are now broken and the same happens if I create a new one.

Change the spaces to underscores in the List Name (double-click a list to Edit).

This was fixed in TB 68.8.

All Replies (20)

Does the list name have any special characters or spaces?

I have the same problem: When I attempt to address an email to a subgroup, ie,

All My Friends it prints as

All My Friends and gives the error message: «

All My Friends is not a valid e-mail address because it is not of the form user@host. You must correct it before sending the e-mail.» I never had this problem before the recent update to version 68.7.0. I eliminated the spaces in the group name, and it worked fine, but it worked fine before with the spaces, so why not now.

All My Friends it prints as

All My Friends and gives the error message: «

All My Friends is not a valid e-mail address because it is not of the form user@host. You must correct it before sending the e-mail.» I never had this problem before the recent update to version 68.7.0. I eliminated the spaces in the group name, and it worked fine, but it worked fine before with the spaces, so why not now.

I guess there was a change between 68.6 and 68.7, although I can’t find any evidence of it.

I am glad I am not the only one. My list name is two words, it has been working fine for years. How can I fix it please. All of my lists are now broken and the same happens if I create a new one.

Modified April 10, 2020 at 3:12:38 PM PDT by steventonpc

Chosen Solution

I am glad I am not the only one. My list name is two words, it has been working fine for years. How can I fix it please. All of my lists are now broken and the same happens if I create a new one.

Change the spaces to underscores in the List Name (double-click a list to Edit).

This was fixed in TB 68.8.

I am glad I am not the only one. My list name is two words, it has been working fine for years. How can I fix it please. All of my lists are now broken and the same happens if I create a new one.

Modified May 7, 2020 at 4:53:35 PM PDT by sfhowes

Thank you that worked! So all future lists will have to have underscores?

I don’t know if spaces will always be disallowed, but a list without spaces or special characters should always work.

I have a mailing list with nine emails. This morning it worked fine. Now instead of putting the email addresses in the To space it puts the name of the List and when I send I get <> is not a valid email address because it is not of the form user@host. You must correct it before sending the email.

I have the same problem. Several lists have disappeared and none are working. They all worked for years! What gives??

I have a mailing list with nine emails. This morning it worked fine. Now instead of putting the email addresses in the To space it puts the name of the List and when I send I get <> is not a valid email address because it is not of the form user@host. You must correct it before sending the email.

I have the same problem. Several lists have disappeared and none are working. They all worked for years! What gives??

None of the above suggestions have worked no matter what I do. I consistently get the error in the attachment.

Double-click the Group List name to edit it; then either delete any spaces within the group name, or change the spaces to underscores. This will make the group work again, but it doesn’t answer my original question as to why, after a zillion years of working with group names with spaces doesn’t it work now with the recent update to 68.7.0. Come on Mozilla, fix it.

Thank you, but this did NOT work. I even deleted the list name, re-entered it with no spaces for the list, description, etc., saved everything and logged off. Logged back in and got the same error! Very frustrating!!

I am also having this problem. My list name is one word. Is there a way to escalate this issue to obtain a resolution. Need to use this function NOW.

I am also having this problem. My list name is one word. Is there a way to escalate this issue to obtain a resolution. Need to use this function NOW.

I am also having this problem. My list name is one word. Is there a way to escalate this issue to obtain a resolution. Need to use this function NOW.

I then moved the list description up into the List nickname field, and suddenly it worked. The mails went out. Now I have not tried yet with putting more descriptive names back into the list name, with spaces etc., but will try as well while leaving the nickname in place.

Modified April 11, 2020 at 6:49:16 PM PDT by endrick

How to Fix an Invalid Email Address: Best Guide 2022 [updated]

Email validation. The reason many email addresses are not accepted in a delivery list, or simply produce a bounce, could be because they are considered invalid. This is not an uncommon problem in marketing campaigns and sign up lists for email delivery.

We already know that we can use services to get rid of them, but the question might remain, how do I fix this issue myself?

Before we can run, we have to walk. So, let’s begin with the basics of an invalid email address.

Table of Contents

What is an invalid email address?

Basically, it’s just an address that doesn’t have the correct format to be an email address, one that doesn’t exist or doesn’t anymore. Dealing with these cases can often lead us to damage a bit of our reputation score with one or many servers.

Before we can tell you how to fix the issue, we must first know what issue we’re dealing with. This is, knowing the cause of the problem. Keep in mind that in the average mailing list about 5 to 30 percent of emails will be invalid.

As you can see, dealing with 30% of invalid emails in a large database is, with no doubt, a very tiring task. Nevertheless if should you want to do it yourself or the database is a small one. Here are the main reasons an email address will be invalid. ensuring the email validation of your list is key to your deliverability.

Five reasons an email address might be invalid.

Email change.

Many people often change their emails for a trendier service. This not always has to be the case. Maybe they wanted a new one or simply because they like another service better than the old one.

This is the top cause an email address is invalid; it simply was deleted because whoever owned has a new one. Sometimes they don’t even delete it, it just becomes inactive due to the lack of use.

Person switched position.

In the case of someone working in a large corporative conglomerate it’s typical that people get assigned an address from the company’s server. If they get promoted or assigned to a different division then that address will likely be removed.

Large companies are not the only ones that do this, small startups, public offices and universities also do it and is more common that you might think at first.

This also applies if the person was fired or no longer has connections with the address due to moving or something else.

The domain is dead.

If the domain es dead, or the server is down temporarily, the address will be considered invalid as there is no domain to link it to.

A dead domain is a sure tell sign of a dead company, filtering emails addresses that are invalid for this reason can also be a good marker that a certain company is out of business.

Email provider or server is dead.

Whether is just down or gone for good, in essence is the same for us. The mail tries to reach a specific server only to not find it. This results in the address not being considered valid.

Sometimes the email providers go out of business, other times is merely a technical issue that will be fixed eventually. But meanwhile the address remains invalid.

Typos in the address.

This IS a very popular cause, since human error can be involved in every step of the process that got us that email. There’s a good chance that someone screw up and put an extra letter in the address. Sometimes there are letters missing, and again this is really not uncommon.

Now that the 5 main reasons are covered, we go about what to do in each scenario.

How do I fix it?

Find another way to communicate.

Most of the time you can find a person on the internet. If you really want that person to receive your emails then you might want to get in touch with them. Likely they just forgot to notify that they changed email.

If this is about a marketing list then you can often find a person via their curriculum in LinkedIn. Other good places could be social media or the company where that person was working.

Notify the company.

If a client just disappeared on you right before you could close a deal, you might want to get in touch with the parent company and ask if everything is okay. Often enough the company just moved the person and the replacement hasn’t arrived or is not up to date with deals and such.

Check domains.

The internet is one of the greatest tools at our disposal, use it to find out if a domain is still active or it’s just a minor problem with their server. Most of the time is nothing, but sometimes domains go down for good and checking will save you precious time and effort.

Do keep in mind that, if the email provider or domain is dead and it looks like it’s going to stay that way. There’s really not much you can do about it, just be quick and move your business somewhere else.

Rely on a service.

Remember there are always services like VerifyBee that can save you time with all the above. If the problem seems beyond the scope of what we’ve stablished here then is likely a job for a professional. Normally any site that verifies emails can also do email validation.

Check for typos and formatting problems.

Sometimes the simplest problem is the hardest to see. Always double check the spelling in every address you input yourself. Where there’s room for human error there’s likely a human error.

Before we go on any further you might want to know what a valid email format is and how to follow it.

Email format and email validation.

Basically, there are three parts for every email address. The local address, the domains name and the identifier of the domain. This parts are checked by every email validation service. Let’s review each briefly.

Using for example this [email protected]

Here the local part is “example-email” and is the name that particular address has inside the domains server. The domain, in this case “testServer”, is the name of the domain the address belongs to. The “.com” is the identifier, basically identifies what kind of domain it is that hosts the recipient server.

Know that in every email there’s the “@” right before the domain. This basically means “at the”. Another way to read this would be “Example-email at the testServer.com domain”.

Every email follows this format and has to contain those parts or else it will be invalid.

Local name. Identifies the address within the domain.
@. “At the”.
Domain. The name of the domain hosting the recipient’s server.
Domain identifier. “.com”, “.org” and others.

Remember to double check.

Follow the syntax from above and your email should be considered valid. So long as the domain exists and the servers are working properly. Check for typos, as they are more common than we would like to admit. If you’re still uncertain you can always turn to VerifyBee and rely on them for email validation.

Having problems with an invalid address can nearly always affect an email marketing campaign. Luckily for you now you know how to counter them in most cases, if all fails just turn to a service and ask for help. Getting the most deliverability possible out of your email marketing list should be a priority for your business.

Email address is not valid

The latest version,when i test request sub i found this issue,Maybe it is a bug?
Some mail address showed its not valid.
like someone@students.solano.edu

I just tried that format of email address and didn’t get an issue.

This is for the “request management link” form, correct? And the email address you tried does have active subscriptions? If there are no active subscriptions for an email address it will show the “Email address is not valid” error.

HI @wpkube
I have try sub without comment…

I tried that one as well, it worked fine.

Can you send over the URL to your site? Trying the subscription might give me an idea as to what’s going on.

Hi @wpkube
This is my link,you can try here

This is weird. The same email on my site works fine but not on yours.

Do you have experience with making modifications to the plugin files? If yes, I can let you know what exactly to add so we can get some additional information on why the email address is seen as invalid.

Hi @wpkube
I have change only one there…
You know, www.google.com can not access from some places,so i change ‘www.google.com’ to www.recaptcha.net …
Like this:
https://github.com/stcr/subscribe-to-comments-reloaded/pull/665#issue-1006633952
note:only google reCAPTCHA site.

In wp_subscribe_realoded.php on line 765 you’ll see:

Just after that line (and before the > else < part which is on line 766) add this:

Then try the form submission again and let me know what’s shown at the top of the content.

You’ll see the full path to the file and at the end it will either say false or show the email address.

It showed string(28) «someone@students.solano.edu»

If it returns the email address then it passes the validity check.

Let’s go down further the subscription process. First, remove the previous change.

Then in templates/subscribe.php on line 72 is:

Just after that add:

And then check again what’s shown (like before).

Nothing is displayed.
And do you have Telegram or discord?

Did that email format work fine before? If yes, then in wp_subscribe_reloaded.php on line 721 you’ll see:

Remove that line and then try again.

That’s something that changed in the latest update and if it worked fine before, should be the cause of the issue.

No, sorry, I don’t use those services. There is a contact form at subscribe-reloaded.com/contact so you can contact us directly via email.

Not work either….
And my email work very fine before i update to the lasted version….

Do you remember which version did you use before?

And you can download the different versions:

First one is from October. Second one March. Third one January.

I don’t think you had an older version that that.

To test a different version you could disable and delete the plugin, then install it using the ZIP package (from the links above).

But, keep in mind that deleting it will also delete your settings. It will not delete subscriptions if you have the “Safely uninstall” option set to “Yes” in WP admin > StCR > Options. But it will delete the settings and restore them back to default when you activate the plugin again.

Alternatively you could use an FTP client to just overwrite the plugin files with the older version files, in that case nothing gets deleted.

After i test…from version 210104…it showed

But version 200813 work fine……..

In version 210104 there was a change to the “request management link” form which will show “email address is not valid” if there’s no subscriber with that email, but that does not apply to “subscribe without comment” form.

Google reCAPTCHA was added to “subsribe without comment” form.

Other than that, no changes related to that functionality were made.

But, it might be related to reCAPTCHA (not sure how but everything is possible), because “Challenge answer is not correct” shouldn’t be showing there.

Can you try disabling reCAPTCHA and then try the email again?

If it makes no difference replace subscribe.php code with this code.

The difference between original (latest version) and the one from the link is just 3 var_dump calls in there at different locations. One location is the same as before, second one at the point where the variable that stores the validity state of the email is set and the third one is inside of the output before the validity is checked and the output “Email address is not valid” is displayed.

How to check for valid email address? [duplicate]

Is there a good way to check a form input using regex to make sure it is a proper style email address? Been searching since last night and everybody that has answered peoples questions regarding this topic also seems to have problems with it if it is a subdomained email address.

18 Answers 18

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There is no point. Even if you can verify that the email address is syntactically valid, you’ll still need to check that it was not mistyped, and that it actually goes to the person you think it does. The only way to do that is to send them an email and have them click a link to verify.

If you want the full check, have a look at this question.

Update: Here’s how you could use any such regex:

Note the r in front of the string; this way, you won’t need to escape things twice.

If you have a large number of regexes to check, it might be faster to compile the regex first:

Another option is to use the validate_email package, which actually contacts the SMTP server to verify that the address exists. This still doesn’t guarantee that it belongs to the right person, though.

It returns a two-tuple containing the real name and the actual address parts of the e-mail:

And if the parsing is unsuccessful, it returns a two-tuple of empty strings:

An issue with this parser is that it’s accepting of anything that is considered as a valid e-mail address for RFC-822 and friends, including many things that are clearly not addressable on the wide Internet:

So, as @TokenMacGuy put it, the only definitive way of checking an e-mail address is to send an e-mail to the expected address and wait for the user to act on the information inside the message.

However, you might want to check for, at least, the presence of an @-sign on the second tuple element, as @bvukelic suggests:

If you want to go a step further, you can install the dnspython project and resolve the mail servers for the e-mail domain (the part after the ‘@’), only trying to send an e-mail if there are actual MX servers: