A true return value does not automatically mean that the user received the email successfully. It just only means that the method used was able to process the request without any errors.
Using the two ‘wp_mail_from’ and ‘wp_mail_from_name’ hooks allow from creating a from address like ‘Name email@example.com‘ when both are set. If just ‘wp_mail_from’ is set, then just the email address will be used with no name.
The default content type is ‘text/plain’ which does not allow using HTML. However, you can set the content type of the email by using the ‘wp_mail_content_type’ filter.
The default charset is based on the charset used on the blog. The charset can be set using the ‘wp_mail_charset’ filter.