Hi, @bugun!
First of all, I’d like to share the main purpose of the WP Mail SMTP plugin. It is to bridge a connection between your WordPress site and your email mailing service (chosen mailer). Simply put, WP Mail SMTP makes it so your site can send emails efficiently. Without the plugin, WordPress can still send email but it does it in a less reliable way. You may end up with emails going into spam or not arriving at all. With WP Mail SMTP, we connect you to an email service that helps to ensure that does not happen.
For example, you have a form on your website -> the user submits it -> sending of the notification email about the submission is triggered -> this email goes to the WP Mail SMTP plugin -> WP Mail SMTP plugin routes this email to the mailer -> mailer will send and deliver it further (so, emails from your site will be sent by mailing service instead of your web host’s server. This improves the reliability and efficiency of your email).
Also, WP Mail SMTP uses the native WordPress wp_mail() function to send emails. It means that any email sent through the wp_mail() function on the website will be routed through our plugin. And almost all form plugins use the same wp_mail() function. So, all you need to make it work is to properly configure the desired mailer in the WP Mail SMTP plugin.
If you want to use “Microsoft 365 / Outlook.com” as a mailer, you can:
1. Use the “Other SMTP” mailer option to connect to your Office 365 / Outlook email account. However, depending on your server configurations, you may run into server-related issues such as blocked ports, firewall, and ModRewrite rules, etc.
or
2. Use the “Outlook” mailer option which makes use of Microsoft’s API. Microsoft’s API is more reliable, secure, and does not often encounter server-related issues when compared to the “Other SMTP” option.
Kind regards.