We are using liferay 7.3.1 on two servers (Dev and Test) and both are configured to send liferay emails (Account creation, email verification, password change and reset) to another server where the emails are saved as eml files. The problem is emails for Dev can be created, but no email for Test are created. Dev and Test have the same settings in portal.ext.properties and C:\Liferay\liferay-ce-portal-7.3.1-ga2\tomcat-9.0.33\conf\Catalina\localhost\ROOT.xml file. In the portal.ext.properties file, we have "mail.session.jndi.name=mail/MailSession". In the liferay Control Panel UI, we see "mail.session.mail" set as "false" (the default value) for Dev and "true" for Test. We thought that might be the cause. So we added "mail.session.mail=false" to portal.ext.properties for Test and restarted liferay, but the "mail.session.mail" was still "true" after that. Can someone offer some advice on the following two questions:

1. Any other possible cause for emails failed to send for Test?

2. How can we set "mail.session.mail" to "false" for our Test server?