As of Zanata 3.7 (https://github.com/zanata/zanata-server/pull/633) email configuration is taken directly from JBoss/WildFly's
standalone.xml configuration, using the mail session configured with the JNDI name
java:jboss/mail/Default. In the default configuration of JBoss/WildFly, this expects an SMTP server on localhost port 25.
The JNDI strings starting with
java:global/zanata/smtp/ are now obsolete. If you have previously configured these values, you will need to change the configuration of the mail session
java:jboss/mail/Default to include your preferred SMTP settings.
JBoss's mail session configuration is described on these pages: