Background
There are many ways to verify email addresses in PHP. The more commonly used one is to write regular expressions yourself. However, regular expressions are troublesome. PHP has its own method for verification.
filter_var
filter_var is a variable filtering method built into PHP. It provides many practical filters and can be used to verify integers, floating point numbers, email addresses, URLs, MAC addresses, etc.
Specific filter reference: filters.validate
If filter_var returns false, it means that the variable cannot pass the filter, which means it is illegal.
$email = "lastchiliarch@163.com"; var_dump(filter_var($email, FILTER_VALIDATE_EMAIL)); $email = "asb"; var_dump(filter_var($email, FILTER_VALIDATE_EMAIL)); $email = "1@a.com"; var_dump(filter_var($email, FILTER_VALIDATE_EMAIL));
Output:
string(21) "lastchiliarch@163.com"
bool(false)
string(7) "1@a.com"
For the illegal email format asb, false is returned, but for 1@a.com, it passes, but there are still some flaws.
However, if the general rules are passed, 1@a.com will be considered to be a legitimate email address. So is there any way to verify it more accurately?
checkdnsrr
checkdnsrr is actually used to query the DNS record of the specified host. We can use it to verify whether the mailbox exists.
For 1@a.com, the MX record definitely does not exist.
$email = "lastchiliarch@163.com"; var_dump(checkdnsrr(array_pop(explode("@",$email)),"MX")); $email = "1@a.com"; var_dump(checkdnsrr(array_pop(explode("@",$email)),"MX"));
Output:
bool(true)
bool(false)
You can see that it is perfect. The only drawback is that it is too slow. After all, it is a network request. Therefore, it is not suitable to use this method to verify a large number of mailboxes simultaneously.
filter_var+checkdnsrr
We can combine filter_var and checkdnsrr for verification. The vast majority of illegal mailboxes will definitely fail when filter_var is used, and the rest can be further judged using
checkdnsrr.
$email_arr = array("lastchiliarch@163.com", "1@a.com"); foreach($email_arr as $email) { if (filter_var($email) === false) { echo "invalid email: $email \n"; continue; } if(checkdnsrr(array_pop(explode("@",$email)),"MX") === false) { echo "invalid email: $email \n"; continue; } }
Output: invalid email: 1@a.com
But it should be noted that since we only check the MX record, we can only judge that 163.com exists, but it cannot explain the lastchiliarch This user exists.
If you want to more accurately determine the existence of the mailbox, you can only connect to the SMTP server to verify it.

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Dreamweaver CS6
Visual web development tools

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

SublimeText3 Linux new version
SublimeText3 Linux latest version

SublimeText3 Mac version
God-level code editing software (SublimeText3)
