ASP.NET Core Web API hosted on Azure don't send an email

Question

我有一個基於 ASP.NET 核心的 Web API 並作為服務托管在 Z3A580F142203677F1F0ZBC308 上。 我有一個發送 email 的簡單功能。 但它只適用於本地主機。 當我在 Azure 上發布它時，POST 查詢返回錯誤：500。

這是一個 MailKit.Net.Smtp 庫。

    {
        [HttpPost]
        [AllowAnonymous]
        public async Task<ActionResult> SendMail([FromBody] Receiver receiver)
        {
            var message = new MimeMessage();
            message.From.Add(new MailboxAddress("Step OSBB", "receiver@gmail.com"));

            message.To.Add(new MailboxAddress("User name", receiver.Email));

            message.Subject = "Henlo, it's a testing email";

            message.Body = new TextPart("plain")
            {
                Text = "I am using MailKit to send this message"
            };

            using (var client = new SmtpClient())
            {
                client.Connect("smtp.gmail.com", 587, false);
                client.Authenticate("myemail@gmail.com", "mypass");
                client.Send(message);
                client.Disconnect(true);
            }
            return StatusCode(200);
        }
    }

    public class Receiver
    {
        public string Email { get; set; }
    }```