is_email_address_unsafe( string $user_email ): bool
- Since
- MU (3.0.0)
- Source
wp-includes/ms-functions.php:399
Description
This function checks against the Banned Email Domains list at wp-admin/network/settings.php. The check is only run on self-registrations; user creation at wp-admin/network/users.php bypasses this check.
Compatibility
- WordPress
- since MU (3.0.0)
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$user_emailstring- The email provided by the user at registration.
Return value
bool- True when the email address is banned, false otherwise.
Performance profile
How much work a call to is_email_address_unsafe() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Scales with input
- Instructions
- 14–57
- Plugin surface
- 1 hook
- Called by
- 1
Reads stored settings via get_site_option(), cached per request but not free on a cold cache.
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 59.
Third-party callbacks on 'is_email_address_unsafe' run inside this call, and their cost is not bounded by anything here.
1 place in core call this, so the cost is paid more often than your own code shows.
What it touches
- optionnetwork option
get_site_option()called directly - hookthird-party callbacks
apply_filters()called directly
Further down the call graph this can also reach cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 6 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost is_email_address_unsafe() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 14–22 | get_site_option(), apply_filters() |
!is_array($banned_names) | 21–27 | get_site_option(), explode(), apply_filters() |
is_array($banned_names) | 39–47 | get_site_option(), array_map(), strtolower(), explode(), apply_filters() |
| always | 46–52 | get_site_option(), explode(), array_map(), strtolower(), explode(), apply_filters() |
is_array($banned_names) && !$banned_names && $email_domain !== false && str_ends_with() | 50–52 | get_site_option(), array_map(), strtolower(), explode(), str_ends_with(), apply_filters() |
!$banned_names && $email_domain !== false && str_ends_with() | 57 | get_site_option(), explode(), array_map(), strtolower(), explode(), str_ends_with(), apply_filters() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 59 | 14–57 | 10 | |
| 8.5 | 59 | 14–57 | 10 | |
| 8.4 | 59 | 14–57 | 10 | 3 fewer instructions than PHP 8.3 |
| 8.3 | 62 | 14–60 | 10 | |
| 8.2 | 62 | 14–60 | 10 | |
| 8.1 | 62 | 14–60 | 10 | |
| 7.4 | 62 | 14–60 | 10 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Hooks and filters fired · 1
One hook fires while is_email_address_unsafe() runs, in this order:
- apply_filters( is_email_address_unsafe )filterline 438 (+39 into the body)
Filters whether an email address is unsafe.
Uses · 3
- get_site_option()Retrieve an option value for the current network based on name of option.
- str_ends_with()Polyfill for `str_ends_with()` function added in PHP 8.0.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 1
- wpmu_validate_user_signup()Sanitizes and validates data required for a user sign-up.
Source code
function is_email_address_unsafe( $user_email ) { $banned_names = get_site_option( 'banned_email_domains' ); if ( $banned_names && ! is_array( $banned_names ) ) { $banned_names = explode( "\n", $banned_names ); } $is_email_address_unsafe = false; if ( $banned_names && is_array( $banned_names ) && false !== strpos( $user_email, '@', 1 ) ) { $banned_names = array_map( 'strtolower', $banned_names ); $normalized_email = strtolower( $user_email ); list( $email_local_part, $email_domain ) = explode( '@', $normalized_email ); foreach ( $banned_names as $banned_domain ) { if ( ! $banned_domain ) { continue; } if ( $email_domain === $banned_domain ) { $is_email_address_unsafe = true; break; } if ( str_ends_with( $normalized_email, ".$banned_domain" ) ) { $is_email_address_unsafe = true; break; } } } /** * Filters whether an email address is unsafe. * * @since 3.5.0 * * @param bool $is_email_address_unsafe Whether the email address is "unsafe". Default false. * @param string $user_email User email address. */ return apply_filters( 'is_email_address_unsafe', $is_email_address_unsafe, $user_email );}Changelog
Introduced in MU (3.0.0). Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/ms-functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
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