<mailer-name>.go

package mailers

import (
        "github.com/gobuffalo/buffalo/mail"
        "github.com/gobuffalo/buffalo/render"
        "github.com/pkg/errors"
)

func SendMailerName() error {
        m := mail.NewMessage()

        // fill in with your stuff:
        m.Subject = "Mailer Name"
        m.From = ""
        m.To = []string{}
        err := m.AddBody(r.HTML("<mailer-name>.html"), render.Data{})
        if err != nil {
                return errors.WithStack(err)
        }
        return smtp.Send(m)
}