watcher的邮件告警在Es配置文件中该如何配置？

邮件服务器我使用Postfix 搭建，Foxmail中可以正常使用
 我在es中配置如下文件，但是节点无法启动。

xpack.notification.email.account:
    work:
        profile: standard
        email_defaults:
            from: ***@***.com
        smtp:
            auth: true
            starttls.enable: true
            host: ******.com
            port: 25
            user: ***@***.com
            password: ********
 
节点报错如下：

[2019-10-11T14:39:57,795][INFO ][o.e.e.NodeEnvironment    ] [Master-Node2] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [15gb], net total_space [16.9gb], types [rootfs]
[2019-10-11T14:39:57,807][INFO ][o.e.e.NodeEnvironment    ] [Master-Node2] heap size [1007.3mb], compressed ordinary object pointers [true]
[2019-10-11T14:39:57,888][INFO ][o.e.n.Node               ] [Master-Node2] node name [Master-Node2], node ID [AHPVf2LsQX-HA1R5Ank2_g], cluster name [Cluster-Group1]
[2019-10-11T14:39:57,889][INFO ][o.e.n.Node               ] [Master-Node2] version[7.2.0], pid[16340], build[default/rpm/508c38a/2019-06-20T15:54:18.811730Z], OS[Linux/3.10.0-957.el7.x86_64/amd64], JVM[Oracle Corporation/OpenJDK 64-Bit Server VM/12.0.1/12.0.1+12]
[2019-10-11T14:39:57,889][INFO ][o.e.n.Node               ] [Master-Node2] JVM home [/usr/share/elasticsearch/jdk]
[2019-10-11T14:39:57,889][INFO ][o.e.n.Node               ] [Master-Node2] JVM arguments [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -Des.networkaddress.cache.ttl=60, -Des.networkaddress.cache.negative.ttl=10, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -XX:-OmitStackTraceInFastThrow, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Djava.io.tmpdir=/tmp/elasticsearch-16711943483148870267, -XX:+HeapDumpOnOutOfMemoryError, -XX:HeapDumpPath=/var/lib/elasticsearch, -XX:ErrorFile=/var/log/elasticsearch/hs_err_pid%p.log, -Xlog:gc*,gc+age=trace,safepoint:file=/var/log/elasticsearch/gc.log:utctime,pid,tags:filecount=32,filesize=64m, -Djava.locale.providers=COMPAT, -Dio.netty.allocator.type=unpooled, -XX:MaxDirectMemorySize=536870912, -Des.path.home=/usr/share/elasticsearch, -Des.path.conf=/etc/elasticsearch, -Des.distribution.flavor=default, -Des.distribution.type=rpm, -Des.bundled_jdk=true]
[2019-10-11T14:40:00,194][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [aggs-matrix-stats]
[2019-10-11T14:40:00,195][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [analysis-common]
[2019-10-11T14:40:00,195][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [data-frame]
[2019-10-11T14:40:00,195][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [ingest-common]
[2019-10-11T14:40:00,195][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [ingest-geoip]
[2019-10-11T14:40:00,195][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [ingest-user-agent]
[2019-10-11T14:40:00,196][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [lang-expression]
[2019-10-11T14:40:00,196][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [lang-mustache]
[2019-10-11T14:40:00,196][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [lang-painless]
[2019-10-11T14:40:00,196][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [mapper-extras]
[2019-10-11T14:40:00,196][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [parent-join]
[2019-10-11T14:40:00,196][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [percolator]
[2019-10-11T14:40:00,197][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [rank-eval]
[2019-10-11T14:40:00,197][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [reindex]
[2019-10-11T14:40:00,197][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [repository-url]
[2019-10-11T14:40:00,197][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [transport-netty4]
[2019-10-11T14:40:00,197][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-ccr]
[2019-10-11T14:40:00,198][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-core]
[2019-10-11T14:40:00,198][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-deprecation]
[2019-10-11T14:40:00,198][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-graph]
[2019-10-11T14:40:00,198][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-ilm]
[2019-10-11T14:40:00,198][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-logstash]
[2019-10-11T14:40:00,198][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-ml]
[2019-10-11T14:40:00,199][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-monitoring]
[2019-10-11T14:40:00,199][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-rollup]
[2019-10-11T14:40:00,199][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-security]
[2019-10-11T14:40:00,199][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-sql]
[2019-10-11T14:40:00,199][INFO ][o.e.p.PluginsService     ] [Master-Node2] loaded module [x-pack-watcher]
[2019-10-11T14:40:00,200][INFO ][o.e.p.PluginsService     ] [Master-Node2] no plugins loaded
[2019-10-11T14:40:02,331][ERROR][o.e.b.Bootstrap          ] [Master-Node2] Exception
java.lang.IllegalArgumentException: unknown setting [xpack.notification.email.account.work.smtp.password] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:531) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:476) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:447) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:418) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.SettingsModule.<init>(SettingsModule.java:148) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.node.Node.<init>(Node.java:342) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.node.Node.<init>(Node.java:251) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:221) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:221) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:349) [elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) [elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) [elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) [elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) [elasticsearch-cli-7.2.0.jar:7.2.0]
at org.elasticsearch.cli.Command.main(Command.java:90) [elasticsearch-cli-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) [elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) [elasticsearch-7.2.0.jar:7.2.0]
[2019-10-11T14:40:02,337][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [Master-Node2] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: unknown setting [xpack.notification.email.account.work.smtp.password] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:163) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-7.2.0.jar:7.2.0]
at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-7.2.0.jar:7.2.0]
Caused by: java.lang.IllegalArgumentException: unknown setting [xpack.notification.email.account.work.smtp.password] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:531) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:476) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:447) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:418) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.common.settings.SettingsModule.<init>(SettingsModule.java:148) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.node.Node.<init>(Node.java:342) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.node.Node.<init>(Node.java:251) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:221) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:221) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:349) ~[elasticsearch-7.2.0.jar:7.2.0]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.2.0.jar:7.2.0]
... 6 more


求大佬指点。