- Plesk for Linux
- The following error appears while sending a test message in Outlook:
CONFIG_TEXT: Send test e-mail message: None of the authentication methods supported by this client are supported by your server.
- TCP port 587 open in firewall.
- TCP port 587 is configured according to How to enable 587 submission port on Linux?
- Mail server configuration was checked with the article SMTP authentication fails on Plesk with SMTP: Authentication methods aren't supported by server.
The error occurs if encryption type is not specified in the mail client.
In the settings of the mail account in Outlook, change the encryption type from
Auto using the below steps:
Open Outlook Settings:
Select your email account from the list and click Change. Email settings should be displayed.
Click More Settings... button.
On the tab Outgoing Server, enable the option My outgoing server (SMTP) requires authentication and select Use same settings as my incoming mail server settings.
On the tab Advanced, set Outgoing server (SMTP) to use port 587 and set Use the following type of encrypted connection to Auto.
Click OK to update the settings.
Click Next and then, click Finish.
If the issue still persists, follow these steps:
Make sure that Enable SMTP service on port 587 on all IP addresses (Enable message submission for Plesk 12.0 and lower) is enabled in Tools & Settings > Mail Server Settings on Plesk server:
Connect to the server via SSH.
In the file
/etc/postfix/main.cf, comment the option
smtpd_sasl_security_optionsand add the line
smtpd_tls_security_level = may.
To apply changes, restart Postfix using the command:
# service postfix restart