Stampie VS flanker

A non-framework-dependent straightforward API Wrapper that is easy to integrate into a PHP application. The API wrapper is used in Postmark, SendGrid, MailGun, Mandrill, and many other third-party email-sending services that can be used in your project.

Stampie - A library for email services such as SendGrid, PostMark, MailGun and Mandrill.

So, it's time to switch to the Mail Service provider. In our case it will be Mailgun. To do this, you just need to register and attach the card to your Mailgun account. After activating your account with the card attached, you can set up a domain for your email.

Mailgun. A developer-focused, scalable, and reliable email sending service.

Link: Mailgun

This guide will describe how to set up Uptime Kuma on Koyeb to monitor your services and send notifications. Uptime Kuma uses a local SQLite database to store user data, configuration for services, and more. We will deploy it alongside Litestream to automatically replicate the data to an S3-compatible bucket hosted on Backblaze's B2 service. We'll use a Mailgun account to set up SMTP details for notifications.

Sendgrid, Mailgun, or Postmark are great solutions if you have a need for transactional emails that are technical. I still prefer using Customer.io for this need. If you’re unsure what transactional emails are, check out this guide.

A Mailgun account. Sign up for a free trial and be sure to verify your email.

Anyway, in answer to your question, you most likely can’t. You should use a mail relay service such as MailGun. https://www.mailgun.com/

You could consider to use some email delivery service like Mailgun or Sendgrid. They offer free tiers and their servers are more accepted than some random self-hosted server.

Visit the Mailgun website and sign up for an account. To create your account, provide the required information, including your email address and password. Mailgun offers different plans, including a free tier with limited features.