smtppool is a Go library that creates a pool of reusable SMTP connections for high throughput e-mailing. It gracefully handles idle connections, timeouts, and retries. The e-mail formatting parsing, and preparation code is forked from jordan-wright/email.
go get github.com/knadh/smtppool
package main
import (
"fmt"
"log"
"github.com/knadh/smtppool"
)
func main() {
// Try https://github.com/mailhog/MailHog for running a local dummy SMTP server.
// Create a new pool.
pool, err := smtppool.New(smtppool.Opt{
Host: "localhost",
Port: 1025,
MaxConns: 10,
IdleTimeout: time.Second * 10,
PoolWaitTimeout: time.Second * 3,
})
if err != nil {
log.Fatalf("error creating pool: %v", err)
}
e:= Email{
From: "John Doe <john@example.com>",
To: []string{"doe@example.com"},
// Optional.
Bcc: []string{"doebcc@example.com"},
Cc: []string{"doecc@example.com"},
Subject: "Hello, World",
Text: []byte("This is a test e-mail"),
HTML: []byte("<strong>This is a test e-mail</strong>"),
}
// Add attachments.
if _, err := e.AttachFile("test.txt"); err != nil {
log.Fatalf("error attaching file: %v", err)
}
if err := pool.Send(e); err != nil {
log.Fatalf("error sending e-mail: %v", err)
}
}Licensed under the MIT license.