turbosmtp
There are 2 repositories under turbosmtp topic.
emiliort/turbosmtp-api-client
PHP library to send mail using Turbo SMTP API v2
dueclic/turbosmtp-for-wordpress
turboSMTP’s official plugin for WordPress is a professional tool that delivers and tracks your transactional emails in real time. It will improve the deliverability of the emails sent from your wordpress cms.