Multi-Email Login

Multi-Email Login is a WordPress plugin that enables users to associate multiple email addresses with a single account and authenticate using any of them. This solves a common problem where users have multiple email addresses (personal, work, legacy accounts) but want to maintain a single WordPress profile.

Why Use Multi-Email Login?

• Flexibility: Users can login with whichever email address they have handy
• Account Consolidation: No need to create separate accounts for different email addresses
• Smooth Transitions: When changing primary email addresses, users can keep both active for seamless access
• Business Use: Perfect for team members who use multiple email addresses across different departments or clients
• Zero Friction: Works transparently with WordPress authentication—no special configuration needed

Features:
* Multiple email addresses per user (unlimited)
* Login with any associated email address
* Seamless WordPress authentication integration
* Unique email enforcement
* User-friendly interface
* No configuration needed
* No WordPress core modifications
* Developer-friendly API for finding users by any email address

Security:
* Email format validation
* Input sanitization
* AJAX nonce protection
* User capability checks
* Password verification
* Duplicate prevention

Developer Usage

The plugin provides a simple API for developers to work with multiple email addresses:

Find a user by any email address (primary or secondary):
$user = melog_get_user_by( ’email’, ‘user@example.com’ );

This function works just like WordPress’s get_user_by() but automatically checks both primary and secondary email addresses.

Instead of:
$user = get_user_by( ’email’, ‘user@example.com’ );

Use:
$user = melog_get_user_by( ’email’, ‘user@example.com’ );

For other field types (login, ID, slug), it behaves identically to the standard WordPress function.