Wordpress E-mail Config

Question

For built-in Wordpress functions such as the "forgot password" option, where is the SMTP server configured? Does it just default to the local daemon? What e-mail does it send messages as?

Answer 1

The default wp_mail() function is pluggable - meaning it can be entirely overridden by plugins. In the absence of any external influence, though, the "from" settings for the email address are hard-coded.

Here's a snippet from /wp-includes/pluggable.php:

// From email and name
// If we don't have a name from the input headers
if ( !isset( $from_name ) )
    $from_name = 'WordPress';

/* If we don't have an email from the input headers default to wordpress@$sitename
 * Some hosts will block outgoing mail from this address if it doesn't exist but
 * there's no easy alternative. Defaulting to admin_email might appear to be another
 * option but some hosts may refuse to relay mail from an unknown domain. See
 * http://trac.wordpress.org/ticket/5007.
 */

if ( !isset( $from_email ) ) {
    // Get the site domain and get rid of www.
    $sitename = strtolower( $_SERVER['SERVER_NAME'] );
    if ( substr( $sitename, 0, 4 ) == 'www.' ) {
        $sitename = substr( $sitename, 4 );
    }

    $from_email = 'wordpress@' . $sitename;
}

// Plugin authors can override the potentially troublesome default
$phpmailer->From     = apply_filters( 'wp_mail_from'     , $from_email );
$phpmailer->FromName = apply_filters( 'wp_mail_from_name', $from_name  );

I showed you this specific snippet for two reasons:

1. It illustrates how the from name and email are set. By default mail is sent from "WordPress" using the address wordpress@sitename.url ... whatever sitename.url might be in your case.
2. It shows that you can filter things a bit.

If you don't want to go the plugin route, you can set up a quick filter in your theme or in a drop-in MU plugin.

add_filter( 'wp_mail_from', 'wp44834_from' );
function wp44834_from( $from_email ) {
    return "myemail@mydomain.com";
}

add_filter( 'wp_mail_from_name', 'wp44834_from_name' );
function wp44834_from_name( $from_name ) {
    return "Bob";
}

These filters will override the built-in defaults and make it appear as if your email actually came from you rather than from WordPress.

Answer 2

WordPress uses php mail by default. To use SMTP you'll need to use a separate plugin, of which there's several available - search WordPress.org and find one that fits your needs.