sendmail

Routes wp_mail() through your provider's SMTP server. Simple settings page, built-in test tool, nothing else.

The SendCloud allows you to send email to your subscribers if your blog has updates. you can monitor the sending email data from data center

A friendly SMTP plugin for WordPress. No third-party, simply using WordPress native possibilities.

Create two textareas, one for create a form template and other for a mail template. The form can be putted in posts, pages or sidebars.