对于 GoDaddy Office365 帐户，您必须使用 GoDaddy 安全 SMTP 服务器:smtpout.secureserver.net

For GoDaddy Office365 accounts you must use the GoDaddy secure SMTP server: smtpout.secureserver.net

请参考https://za.godaddy.com/help/server-and-port-settings-for-workspace-email-6949.