Kotlinmailer Logo Kotlinmailer Logo

Kotlinmailer is a Kotlin Mail API, using coroutines and providing DSLs. It may be used in a Ktor Backend for verification mails.

This project is a hard fork from SimpleKotlinMail which is no more actively worked on.


  • build emails
  • send emails (using an external SMTP server)
  • TLS support

To get started, visit the Documentation.


The purpose of the following code snippets is to provide an insight into the API. However, they are not suitable for learning the API, you should use the actual documentation for this.


Build an email:

val email = emailBuilder {
    from("[email protected]")
    to("[email protected]")

    withSubject("Important question")
    withPlainText("Hey, how are you doing?")


Send that email:

suspend fun main() = email.send()


// EML String -> Email
// MimeMessage -> Email


Inside the email builder, you can easily access kotlinx.html:

emailBuilder {
    withHTML {
        div {
            h1 { +"Really important question!" }
            p { +"Hey, how are you doing?" }

And more

To learn more about Kotlinmailer, visit the Documentation.

Project information

This project uses SimpleJavaMail to deal with java MimeMessages in a more elegant way. On the server side, this projects depends on a fork of SubEthaSMTP.

If you use the documented functionality of SimpleKotlinMail, everything will make use of kotlinx.coroutines.


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