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Direct Mail:SMTP service addresses

Last Updated:Oct 29, 2025

This topic describes the SMTP service addresses for different regions.

Region

Address

China (Hangzhou)

smtpdm.aliyun.com

Singapore

smtpdm-ap-southeast-1.aliyuncs.com

US (Virginia)

smtpdm-us-east-1.aliyuncs.com

Germany (Frankfurt)

smtpdm-eu-central-1.aliyuncs.com

The available SMTP ports are 25, 80, and 465 (SSL encryption).

Note
  • For security reasons, port 25 is disabled by default on ECS instances. If you deploy your reflector on an Alibaba Cloud ECS instance, use port 80 if SSL is disabled or port 465 if SSL is enabled. The same applies to Web Hosting servers.

  • Additionally, the STARTTLS command enables explicit SSL/TLS on port 25 or 80.

Select the server address that corresponds to the service region you chose in the console.

For information about sending emails from China (Hong Kong) and other regions, see How to select a sending region.

Note

Legacy endpoints (not recommended for new users):

  • Singapore: smtpdm-ap-southeast-1.aliyun.com

  • Australia (Sydney): smtpdm-ap-southeast-2.aliyun.com

If you experience connection issues, you can use the following commands to test the network and port. Replace the server address and port with the ones you are using:

ping smtpdm.aliyun.com

telnet smtpdm.aliyun.com 465

mtr -n -i 1 -c 100 smtpdm.aliyun.com