參考網頁：
Gmail example javamail-configuration.properties – OpenNMS
雜亂的學習筆記本: OpenNMS – OpenNMS 基礎應用篇(01) – Notification 設定
Shunze 學園 – 《二》設定notification郵件通知
1. 備份原檔
# cp /opt/opennms/etc/javamail-configuration.properties /opt/opennms/etc/javamail-configuration.properties.$(date +%F)
2. 修改設定檔 /opt/opennms/etc/javamail-configuration.properties
# vim /opt/opennms/etc/javamail-configuration.properties
把
#org.opennms.core.utils.mailHost=127.0.0.1
#org.opennms.core.utils.transport=smtp
#org.opennms.core.utils.smtpport=25
#org.opennms.core.utils.smtpssl.enable=false
#org.opennms.core.utils.authenticate=false
#org.opennms.core.utils.authenticateUser=opennms
#org.opennms.core.utils.authenticatePassword=opennms
#org.opennms.core.utils.starttls.enable=false
#org.opennms.core.utils.messageContentType=text/plain
#org.opennms.core.utils.charset=us-ascii
[@more@]修改成
org.opennms.core.utils.mailHost=smtp.gmail.com
org.opennms.core.utils.transport=smtps
org.opennms.core.utils.smtpport=465
org.opennms.core.utils.smtpssl.enable=true
org.opennms.core.utils.authenticate=true
org.opennms.core.utils.authenticateUser=帳號@gmail.com
org.opennms.core.utils.authenticatePassword=密碼
org.opennms.core.utils.starttls.enabe=true
org.opennms.core.utils.messageContentType=text/html
org.opennms.core.utils.charset=UTF-8
或
org.opennms.core.utils.mailHost=smtp.gmail.com
org.opennms.core.utils.transport=smtp
org.opennms.core.utils.smtpport=587
org.opennms.core.utils.smtpssl.enable=false
org.opennms.core.utils.authenticate=true
org.opennms.core.utils.authenticateUser=帳號@gmail.com
org.opennms.core.utils.authenticatePassword=密碼
org.opennms.core.utils.starttls.enabe=true
org.opennms.core.utils.messageContentType=text/html
org.opennms.core.utils.charset=UTF-8
3. 重新啟動 OpenNMS
# systemctl restart opennms.service
4. 收到的警告信件