SMTP EndPoint (East China): smtpdm.aliyun.com
SMTP EndPoint (Singapore): smtpdm-ap-southeast-1.aliyun.com
SMTP EndPoint (Sydney): smtpdm-ap-southeast-2.aliyun.com
SMTP port: 25, 80, 465 (SSL encrypted).
Note: Port 25 is currently disabled for security reasons specific to ECS. If your sending application is deployed on Alibaba Cloud ECS, we recommend that you use port 80 when SSL is not checked, and use port 465 when SSL is checked. Ditto for cloud virtual host server. Besides, we support explict ssl/tls functionality on port 25 or 80 with “STARTTLS” smtp cmd.