Mailto URL displayed incorrectly in header

In the WordPress dashboard, I go to Appearance -> Customize. There is the section “Social Media Icons”, with the field labeled “Enter your Mailto url”. If I enter an email address here, then the email link is displayed in the header with “https://” prefix on the link. If I try to enter the email with “mailto:” prefix myself, the email link is not displayed. Problem is that the email is displayed by header.php with

echo esc_url($email)

but this should be something like

echo esc_url('mailto:' . $email)

and so you can keep validation using is_email($email).