Jenkins test email fails but build email is sent

I have configured my Jenkins Extended E-mail Notification as below

SMTP SERVER: smtp.gmail.com 
Use SMTP Authentication: ticked
User Name: ***@gmail.com 
Password: ***
USE SSL: ticked
PORT: 465
Charset: UTF-8

I have added my ***@outlook.com email as recipient. My build runs and sends the email shown under Console Output

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  10.608 s
[INFO] Finished at: 2019-05-03T11:32:20+01:00
[INFO] ------------------------------------------------------------------------
Waiting for Jenkins to finish collecting data
[JENKINS] Archiving C:\Users\qureshiz\ECLIPSE\Workspace\CucumberReports\pom.xml to Cucumber_Selenium/Cucumber_Selenium/0.0.1-SNAPSHOT/Cucumber_Selenium-0.0.1-SNAPSHOT.pom
[JENKINS] Archiving C:\Users\qureshiz\ECLIPSE\Workspace\CucumberReports\target\Cucumber_Selenium-0.0.1-SNAPSHOT.jar to Cucumber_Selenium/Cucumber_Selenium/0.0.1-SNAPSHOT/Cucumber_Selenium-0.0.1-SNAPSHOT.jar
channel stopped
Email was triggered for: Always
Sending email for trigger: Always
Sending email to: ***@outlook.com
Finished: SUCCESS

But for some reason my test email gets refused. I'm wondering what the problem is as I don't receive the email too. Any suggestion would be appreciated

Failed to send out e-mail

java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:286)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:231)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1900)

Caused: javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
  nested exception is:
    java.net.ConnectException: Connection refused: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1934)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:638)