go-simple-mail 包提供了一种简便的方式来处理和发送邮件。这个包支持保持活动连接、TLS和SSL加密协议，非常适合批量SMTP邮件发送需求。 

1、安装Go-Simple-Mail包

go get -u github.com/xhit/go-simple-mail/v2

2、配置SMTP服务器连接

go-simple-mail包支持多种SMTP服务器连接的配置，包括TLS和SSL。 

package mainimport (mail "github.com/xhit/go-simple-mail/v2""log""time"
)func main() {server := mail.NewSMTPClient()server.Host = "smtp.example.com"server.Port = 587 // 或者465(SSL)server.Username = "your-email@example.com"server.Password = "your-email-password"server.Encryption = mail.EncryptionTLS // 可以用 mail.EncryptionNone, mail.EncryptionSSL, mail.EncryptionTLSserver.KeepAlive = trueserver.ConnectTimeout = 10 * time.Secondserver.SendTimeout = 10 * time.Seconds