# Skip Oversized Email Attachments

> Removes attachments that would make an email larger than your mail server accepts and notes it in the message, so the email still arrives instead of bouncing.

- Type: PHP
- Runs: Run everywhere
- Category: [Email](https://wpide.com/library/category/email/)
- Tags: email, attachments, deliverability
- Author: WPIDE Team
- Installs: 0
- Updated: 2026-10-28
- Page: https://wpide.com/library/email-attachment-size-guard/

## Code

```php
$wpide_attachment_limit_mb = 15;

add_filter( 'wp_mail', function ( $atts ) use ( $wpide_attachment_limit_mb ) {
    if ( empty( $atts['attachments'] ) ) {
        return $atts;
    }

    $files   = is_array( $atts['attachments'] ) ? $atts['attachments'] : explode( "\n", str_replace( "\r\n", "\n", (string) $atts['attachments'] ) );
    $budget  = $wpide_attachment_limit_mb * MB_IN_BYTES;
    $kept    = array();
    $dropped = array();
    $used    = 0;

    foreach ( $files as $key => $file ) {
        $size = is_readable( $file ) ? (int) ceil( filesize( $file ) * 1.37 ) : 0;
        if ( $used + $size > $budget ) {
            $dropped[] = basename( $file );
            continue;
        }
        $used        += $size;
        $kept[ $key ] = $file;
    }

    if ( $dropped ) {
        $atts['attachments'] = $kept;
        $atts['message']    .= "\n\n(" . count( $dropped ) . ' attachment(s) were too large to send: ' . implode( ', ', $dropped ) . ')';
    }

    return $atts;
}, 40 );
```

## Notes

Set the limit a little below your provider's maximum (often 10 to 25 MB); base64 encoding makes attachments about a third larger, which the snippet accounts for.

## How to use it

Install the free WPIDE plugin (https://wordpress.org/plugins/wpide/), find "Skip Oversized Email Attachments" in its snippet library and add it in one click; or create a new PHP snippet in WPIDE (or any code snippets plugin) and paste the code above. More snippets: https://wpide.com/library/