【Important】Email server disabled the Open Relay function on October 6, 2026.
To enhance campus network information security and comply with the Ministry of Education's cybersecurity audit standards, the email server disabled the Open Relay function on October 6, 2026. Except for applying for a whitelist, all other applications require account and password verification.This measure is necessary to prevent our servers from being exploited for spam, which could lead to the email server IP address being blacklisted and disrupting normal email communications.
The scope of influence includes Faculty and Staff email (@dragon.nchu.edu.tw, @nchu.edu.tw) and Students email (@mail.nchu.edu.tw) server.
If you find that you are unable to send emails and receive the ⚠️504 Authentication failed for SMTP service message, it means that your settings are incorrect. Please refer to the following impact factors for confirmation:
- Webmail Users: No action required. You are not affected.
- Email Software/App Users (e.g., Outlook, Mobile Apps): Please check your settings. Ensure that your [SMTP Service] is configured with [Username and Password authentication]. Failure to do so will result in an inability to send emails after the deadline. (Outlook and mobile phone related settings tutorial)
- Server/System/Website Administrators/Network printer(scanner): If you use our email server [SMTP Service] to send emails via the server name dragon.nchu.edu.tw or mail.nchu.edu.tw, please confirm that account and password verification has been added to the program.
If you have special requirements that prevent you from setting up verification, please contact the Network Division of the Computer and Information Network Center to apply for a whitelist.
👉For detailed instructions and setup guides, please visit: https://webmail.nchu.edu.tw/or/openrelay_en.html
If you have any questions, please feel free to contact us.
Sincerely,
Network Division, Computer and Information Network Center