Unlike Jira, Configuration of a Mail Server does not allow for configuration or disabling of the SMTP timeout value. This timeout value sometimes needs to be adjusted or even disabled in normal SMTP configuration, particularly when sending out emails to a large distribution.

The only way to configure SMTP timeout in Confluence 3.5 is via an undocumented JNDI configuration option (refer to CSP-59724 ). SMTP Timeout is a standard option for configuring SMTP and should be available in the GUI in the standard setup options.