Sending emails

Mailer methods start the SendEmailWorkflow in the background. The generated code resembles:

func (m *WelcomeMailer) SendWelcome(ctx context.Context, vars types.WelcomeMailerSendWelcomeParams) error {
    return triggerWorkflow(ctx, m.client, vars, vars.To, "SendWelcome", "welcome_send_welcome")
}

Calling SendWelcome returns as soon as the workflow has been scheduled. The actual SMTP transaction happens inside the workflow which retries on failure. Inside the workflow, the SendEmailActivity is executed with a retry policy of three attempts.