“smtp-alternative”

WordPress plugin that sends wp_mail() through a JMAP server such as Stalwart instead of SMTP.

Send all WordPress email through the Cloudflare Email Sending API and log every message. Configure via wp-config.php — no admin settings.

Sendelva – Email Delivery for Microsoft 365. WordPress email through Microsoft Graph with app-only OAuth, no SMTP. On WordPress.org. Formerly Graph Mailer. GPL-2.0.

Missivus for WordPress — send WordPress email through Microsoft Graph with application permissions and a shared mailbox. No SMTP, no user login. Free, GPLv3.

Inklura Mail — route wp_mail through bext managed email, with a log. Multisite + self-updating.

Routes WordPress emails through the Cloudflare Email Service REST API.

Replace WordPress default mail functionality with the Web3Forms API

Send WordPress emails via Azure Communication Services (ACS). A reliable, scalable alternative to SMTP.

PostShiba WordPress plugin. Mirror of postshiba/sdks packages/wordpress. Open PRs on postshiba/sdks.

Wordpress plugin to use Ongage Emailing system instead of native WP_MAIL. It uses transnational emails API. https://apidocs.ongage.net/class-Controller_API_Notify_Transactions.html

Wesender Wordpress Email Plugin

This is inboxwp plugin. The easiest solution to send transactional emails in WordPress